Programs & Examples On #Activity indicator

Android view pager with page indicator

Just an improvement to the nice answer given by @vuhung3990. I implemented the solution and works great but if I touch one radio button it will be selected and nothing happens.

I suggest to also change page when a radio button is tapped. To do this, simply add a listener to the radioGroup:

mPager = (ViewPager) findViewById(R.id.pager);
final RadioGroup radioGroup = (RadioGroup)findViewById(R.id.radiogroup);    
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId) {
                    case R.id.radioButton :
                        mPager.setCurrentItem(0, true);
                        break;
                    case R.id.radioButton2 :
                        mPager.setCurrentItem(1, true);
                        break;
                    case R.id.radioButton3 :
                        mPager.setCurrentItem(2, true);
                        break;
                }
            }
        });

Select rows from a data frame based on values in a vector

Similar to above, using filter from dplyr:

filter(df, fct %in% vc)

Python Error: unsupported operand type(s) for +: 'int' and 'NoneType'

I got a similar error with '/' operand while processing images. I discovered the folder included a text file created by the 'XnView' image viewer. So, this kind of error occurs when some object is not the kind of object expected.

.setAttribute("disabled", false); changes editable attribute to false

Try doing this instead:

function enable(id)
{
    var eleman = document.getElementById(id);
    eleman.removeAttribute("disabled");        
}

To enable an element you have to remove the disabled attribute. Setting it to false still means it is disabled.

http://jsfiddle.net/SRK2c/

Cannot install Aptana Studio 3.6 on Windows

Right click the installer and choose "Run as administrator". I suspect it needs administrator account to download and install Node JS during installation.

Vue 2 - Mutating props vue-warn

Vue.js considers this an anti-pattern. For example, declaring and setting some props like

this.propsVal = 'new Props Value'

So to solve this issue you have to take in a value from the props to the data or the computed property of a Vue instance, like this:

props: ['propsVal'],
data: function() {
   return {
       propVal: this.propsVal
   };
},
methods: {
...
}

This will definitely work.

Android EditText Hint

You can use the concept of selector. onFocus removes the hint.

android:hint="Email"

So when TextView has focus, or has user input (i.e. not empty) the hint will not display.

clear data inside text file in c++

If you simply open the file for writing with the truncate-option, you'll delete the content.

std::ofstream ofs;
ofs.open("test.txt", std::ofstream::out | std::ofstream::trunc);
ofs.close();

http://www.cplusplus.com/reference/fstream/ofstream/open/

Git push requires username and password

A common cause is cloning using the default (HTTPS) instead of SSH. You can correct this by going to your repository, clicking "Clone or download", then clicking the "Use SSH" button above the URL field and updating the URL of your origin remote like this:

git remote set-url origin [email protected]:username/repo.git

This is documented at GitHub: Switching remote URLs from HTTPS to SSH.

Batch file to copy directories recursively

After reading the accepted answer's comments, I tried the robocopy command, which worked for me (using the standard command prompt from Windows 7 64 bits SP 1):

robocopy source_dir dest_dir /s /e

Gets byte array from a ByteBuffer in java

As simple as that

  private static byte[] getByteArrayFromByteBuffer(ByteBuffer byteBuffer) {
    byte[] bytesArray = new byte[byteBuffer.remaining()];
    byteBuffer.get(bytesArray, 0, bytesArray.length);
    return bytesArray;
}

Why am I not getting a java.util.ConcurrentModificationException in this example?

One way to handle it it to remove something from a copy of a Collection (not Collection itself), if applicable. Clone the original collection it to make a copy via a Constructor.

This exception may be thrown by methods that have detected concurrent modification of an object when such modification is not permissible.

For your specific case, first off, i don't think final is a way to go considering you intend to modify the list past declaration

private static final List<Integer> integerList;

Also consider modifying a copy instead of the original list.

List<Integer> copy = new ArrayList<Integer>(integerList);

for(Integer integer : integerList) {
    if(integer.equals(remove)) {                
        copy.remove(integer);
    }
}

PHP Try and Catch for SQL Insert

You can implement throwing exceptions on mysql query fail on your own. What you need is to write a wrapper for mysql_query function, e.g.:

// user defined. corresponding MySQL errno for duplicate key entry
const MYSQL_DUPLICATE_KEY_ENTRY = 1022;

// user defined MySQL exceptions
class MySQLException extends Exception {}
class MySQLDuplicateKeyException extends MySQLException {}

function my_mysql_query($query, $conn=false) {
    $res = mysql_query($query, $conn);
    if (!$res) {
        $errno = mysql_errno($conn);
        $error = mysql_error($conn);
        switch ($errno) {
        case MYSQL_DUPLICATE_KEY_ENTRY:
            throw new MySQLDuplicateKeyException($error, $errno);
            break;
        default:
            throw MySQLException($error, $errno);
            break;
        }
    }
    // ...
    // doing something
    // ...
    if ($something_is_wrong) {
        throw new Exception("Logic exception while performing query result processing");
    }

}

try {
    mysql_query("INSERT INTO redirects SET ua_string = '$ua_string'")
}
catch (MySQLDuplicateKeyException $e) {
    // duplicate entry exception
    $e->getMessage();
}
catch (MySQLException $e) {
    // other mysql exception (not duplicate key entry)
    $e->getMessage();
}
catch (Exception $e) {
    // not a MySQL exception
    $e->getMessage();
}

How to tackle daylight savings using TimeZone in Java

public static float calculateTimeZone(String deviceTimeZone) {
    float ONE_HOUR_MILLIS = 60 * 60 * 1000;

    // Current timezone and date
    TimeZone timeZone = TimeZone.getTimeZone(deviceTimeZone);
    Date nowDate = new Date();
    float offsetFromUtc = timeZone.getOffset(nowDate.getTime()) / ONE_HOUR_MILLIS;

    // Daylight Saving time
    if (timeZone.useDaylightTime()) {
        // DST is used
        // I'm saving this is preferences for later use

        // save the offset value to use it later
        float dstOffset = timeZone.getDSTSavings() / ONE_HOUR_MILLIS;
        // DstOffsetValue = dstOffset
        // I'm saving this is preferences for later use
        // save that now we are in DST mode
        if (timeZone.inDaylightTime(nowDate)) {
            Log.e(Utility.class.getName(), "in Daylight Time");
            return -(ONE_HOUR_MILLIS * dstOffset);
        } else {
            Log.e(Utility.class.getName(), "not in Daylight Time");
            return 0;
        }
    } else
        return 0;
}

swift How to remove optional String Character

I looked over this again and i'm simplifying my answer. I think most the answers here are missing the point. You usually want to print whether or not your variable has a value and you also want your program not to crash if it doesn't (so don't use !). Here just do this

    print("color: \(color ?? "")")

This will give you blank or the value.

How to use requirements.txt to install all dependencies in a python project

(Taken from my comment)

pip won't handle system level dependencies. You'll have to apt-get install libfreetype6-dev before continuing. (It even says so right in your output. Try skimming over it for such errors next time, usually build outputs are very detailed)

How do you access the matched groups in a JavaScript regular expression?

_x000D_
_x000D_
var myString = "something format_abc";_x000D_
var arr = myString.match(/\bformat_(.*?)\b/);_x000D_
console.log(arr[0] + " " + arr[1]);
_x000D_
_x000D_
_x000D_

The \b isn't exactly the same thing. (It works on --format_foo/, but doesn't work on format_a_b) But I wanted to show an alternative to your expression, which is fine. Of course, the match call is the important thing.

display:inline vs display:block

By default, inline elements do not force a new line to begin in the document flow. Block elements, on the other hand, typically cause a line break to occur you can refer this link

Fill Combobox from database

To use the Combobox in the way you intend, you could pass in an object to the cmbTripName.Items.Add method.

That object should have FleetID and FleetName properties:

while (drd.Read())
{
    cmbTripName.Items.Add(new Fleet(drd["FleetID"].ToString(), drd["FleetName"].ToString()));
}
cmbTripName.ValueMember = "FleetId";
cmbTripName.DisplayMember = "FleetName";

The Fleet Class:

class Fleet
{
     public Fleet(string fleetId, string fleetName)
     {
           FleetId = fleetId;
           FleetName = fleetName
     }
     public string FleetId {get;set;}
     public string FleetName {get;set;}
}

Or, You could probably do away with the need for a Fleet class completely by using an anonymous type...

while (drd.Read())
{
    cmbTripName.Items.Add(new {FleetId = drd["FleetID"].ToString(), FleetName = drd["FleetName"].ToString()});
}
cmbTripName.ValueMember = "FleetId";
cmbTripName.DisplayMember = "FleetName";

PyCharm import external library

I wanted to add an import path, for another project elsewhere in my workspace. MacOS Catalina 10.15.5 PyCharm Community 2020.1.1

PyCharm - Preferences - Project interpreter - Cog symbol - Show All

At the bottom of that dialog, it shows 5 buttons: Plus, Minus, Pencil, Funnel, and Directory tree.

Click Directory tree. You can now use the Plus button in the new dialog to add your 'external library' search path.

If successful, you should now see the directory name in the "External Libraries" pane in the Project panel.

filedialog, tkinter and opening files

The exception you get is telling you filedialog is not in your namespace. filedialog (and btw messagebox) is a tkinter module, so it is not imported just with from tkinter import *

>>> from tkinter import *
>>> filedialog
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
NameError: name 'filedialog' is not defined
>>> 

you should use for example:

>>> from tkinter import filedialog
>>> filedialog
<module 'tkinter.filedialog' from 'C:\Python32\lib\tkinter\filedialog.py'>
>>>

or

>>> import tkinter.filedialog as fdialog

or

>>> from tkinter.filedialog import askopenfilename

So this would do for your browse button:

from tkinter import *
from tkinter.filedialog import askopenfilename
from tkinter.messagebox import showerror

class MyFrame(Frame):
    def __init__(self):
        Frame.__init__(self)
        self.master.title("Example")
        self.master.rowconfigure(5, weight=1)
        self.master.columnconfigure(5, weight=1)
        self.grid(sticky=W+E+N+S)

        self.button = Button(self, text="Browse", command=self.load_file, width=10)
        self.button.grid(row=1, column=0, sticky=W)

    def load_file(self):
        fname = askopenfilename(filetypes=(("Template files", "*.tplate"),
                                           ("HTML files", "*.html;*.htm"),
                                           ("All files", "*.*") ))
        if fname:
            try:
                print("""here it comes: self.settings["template"].set(fname)""")
            except:                     # <- naked except is a bad idea
                showerror("Open Source File", "Failed to read file\n'%s'" % fname)
            return


if __name__ == "__main__":
    MyFrame().mainloop()

enter image description here

How can I suppress the newline after a print statement?

The question asks: "How can it be done in Python 3?"

Use this construct with Python 3.x:

for item in [1,2,3,4]:
    print(item, " ", end="")

This will generate:

1  2  3  4

See this Python doc for more information:

Old: print x,           # Trailing comma suppresses newline
New: print(x, end=" ")  # Appends a space instead of a newline

--

Aside:

in addition, the print() function also offers the sep parameter that lets one specify how individual items to be printed should be separated. E.g.,

In [21]: print('this','is', 'a', 'test')  # default single space between items
this is a test

In [22]: print('this','is', 'a', 'test', sep="") # no spaces between items
thisisatest

In [22]: print('this','is', 'a', 'test', sep="--*--") # user specified separation
this--*--is--*--a--*--test

Fast check for NaN in NumPy

Ray's solution is good. However, on my machine it is about 2.5x faster to use numpy.sum in place of numpy.min:

In [13]: %timeit np.isnan(np.min(x))
1000 loops, best of 3: 244 us per loop

In [14]: %timeit np.isnan(np.sum(x))
10000 loops, best of 3: 97.3 us per loop

Unlike min, sum doesn't require branching, which on modern hardware tends to be pretty expensive. This is probably the reason why sum is faster.

edit The above test was performed with a single NaN right in the middle of the array.

It is interesting to note that min is slower in the presence of NaNs than in their absence. It also seems to get slower as NaNs get closer to the start of the array. On the other hand, sum's throughput seems constant regardless of whether there are NaNs and where they're located:

In [40]: x = np.random.rand(100000)

In [41]: %timeit np.isnan(np.min(x))
10000 loops, best of 3: 153 us per loop

In [42]: %timeit np.isnan(np.sum(x))
10000 loops, best of 3: 95.9 us per loop

In [43]: x[50000] = np.nan

In [44]: %timeit np.isnan(np.min(x))
1000 loops, best of 3: 239 us per loop

In [45]: %timeit np.isnan(np.sum(x))
10000 loops, best of 3: 95.8 us per loop

In [46]: x[0] = np.nan

In [47]: %timeit np.isnan(np.min(x))
1000 loops, best of 3: 326 us per loop

In [48]: %timeit np.isnan(np.sum(x))
10000 loops, best of 3: 95.9 us per loop

How to reset radiobuttons in jQuery so that none is checked

The best way to set radiobuttons state in jquery:

HTML:

<input type="radio" name="color" value="orange" /> Orange 
<input type="radio" name="color" value="pink" /> Pink 
<input type="radio" name="color" value="black" /> Black
<input type="radio" name="color" value="pinkish purple" /> Pinkish Purple

Jquery (1.4+) code to pre-select one button :

var presetValue = "black";
$("[name=color]").filter("[value='"+presetValue+"']").attr("checked","checked");

In Jquery 1.6+ code the .prop() method is preferred :

var presetValue = "black";
$("[name=color]").filter("[value='"+presetValue+"']").prop("checked",true);

To unselect the buttons :

$("[name=color]").removeAttr("checked");

libaio.so.1: cannot open shared object file

Here on a openSuse 12.3 the solution was installing the 32-bit version of libaio in addition. Oracle seems to need this now, although on 12.1 it run without the 32-bit version.

What is the right way to write my script 'src' url for a local development environment?

This is an old post but...

You can reference the working directory (the folder the .html file is located in) with ./, and the directory above that with ../

Example directory structure:

/html/public/
- index.html
- script2.js
- js/
   - script.js

To load script.js from inside index.html:

<script type="text/javascript" src="./js/script.js">

This goes to the current working directory (location of index.html) and then to the js folder, and then finds the script.

You could also specify ../ to go one directory above the working directory, to load things from there. But that is unusual.

How to insert current datetime in postgresql insert query

You can of course format the result of current_timestamp(). Please have a look at the various formatting functions in the official documentation.

how to disable DIV element and everything inside

You can't use "disable" to disable a click event. I don't know how or if it worked in IE6-9, but it didn't work on Chrome, and it shouldn't work on IE10 like that.

You can disable the onclick event, too, by attaching an event that cancels:

;(function () {
    function cancel () { return false; };
    document.getElementById("test").disabled = true;
    var nodes = document.getElementById("test").getElementsByTagName('*');
    console.log(nodes);
    for (var i = 0; i < nodes.length; i++) {
        nodes[i].setAttribute('disabled', true);
        nodes[i].onclick = cancel;
    }
}());

Furthermore, setting "disabled" on a node directly doesn't necessarily add the attribute- using setAttribute does.

http://jsfiddle.net/2fPZu/

Why does pycharm propose to change method to static

The reason why Pycharm make it as a warning because Python will pass self as the first argument when calling a none static method (not add @staticmethod). Pycharm knows it.

Example:

class T:
    def test():
        print "i am a normal method!"

t = T()
t.test()
output:
Traceback (most recent call last):
  File "F:/Workspace/test_script/test.py", line 28, in <module>
    T().test()
TypeError: test() takes no arguments (1 given)

I'm from Java, in Java "self" is called "this", you don't need write self(or this) as argument in class method. You can just call self as you need inside the method. But Python "has to" pass self as a method argument.

By understanding this you don't need any Workaround as @BobStein answer.

onclick="location.href='link.html'" does not load page in Safari

Try this:

onclick="javascript:location.href='http://www.uol.com.br/'"

Worked fine for me in Firefox, Chrome and IE (wow!!)

Convert timestamp to date in MySQL query

You should convert timestamp to date.

select FROM_UNIXTIME(user.registration, '%Y-%m-%d %H:%i:%s') AS 'date_formatted'

FROM_UNIXTIME

How to find the index of an element in an array in Java?

Simplest solution:

Convert array to list and you can get position of an element.

List<String> abcd  = Arrays.asList(yourArray);
int i = abcd.indexOf("abcd");

Other solution, you can iterator array:

int position = 0;
for (String obj : yourArray) {
    if (obj.equals("abcd") {
    return position;
    }
    position += 1;
} 

//OR
for (int i = 0; i < yourArray.length; i++) {
    if (obj.equals("abcd") {
       return i;
    }
}

ios Upload Image and Text using HTTP POST

Here is a Swift version. Note that if you do not want to send form data it is still important to send the empty form boundary. Flask in particular expects form data followed by file data and will not populate request.files without the first boundary.

  let composedData = NSMutableData()

  // Set content type header
  let BoundaryConstant = "--------------------------3d74a90a3bfb8696"
  let contentType = "multipart/form-data; boundary=\(BoundaryConstant)"
  request.setValue(contentType, forHTTPHeaderField: "Content-Type")

  // Empty form boundary
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  // Build multipart form to send image
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Disposition: form-data; name=\"file\"; filename=\"image.jpg\"\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Type: image/jpeg\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData(rawData!)
  composedData.appendData("\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("--\(BoundaryConstant)--\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  request.HTTPBody = composedData

  // Get content length
  let length = "\(composedData.length)"
  request.setValue(length, forHTTPHeaderField: "Content-Length")

How to Convert the value in DataTable into a string array in c#

If that's all what you want to do, you don't need to convert it into an array. You can just access it as:

string myData=yourDataTable.Rows[0][1].ToString();//Gives you USA

MySQL vs MongoDB 1000 reads

MongoDB is not magically faster. If you store the same data, organised in basically the same fashion, and access it exactly the same way, then you really shouldn't expect your results to be wildly different. After all, MySQL and MongoDB are both GPL, so if Mongo had some magically better IO code in it, then the MySQL team could just incorporate it into their codebase.

People are seeing real world MongoDB performance largely because MongoDB allows you to query in a different manner that is more sensible to your workload.

For example, consider a design that persisted a lot of information about a complicated entity in a normalised fashion. This could easily use dozens of tables in MySQL (or any relational db) to store the data in normal form, with many indexes needed to ensure relational integrity between tables.

Now consider the same design with a document store. If all of those related tables are subordinate to the main table (and they often are), then you might be able to model the data such that the entire entity is stored in a single document. In MongoDB you can store this as a single document, in a single collection. This is where MongoDB starts enabling superior performance.

In MongoDB, to retrieve the whole entity, you have to perform:

  • One index lookup on the collection (assuming the entity is fetched by id)
  • Retrieve the contents of one database page (the actual binary json document)

So a b-tree lookup, and a binary page read. Log(n) + 1 IOs. If the indexes can reside entirely in memory, then 1 IO.

In MySQL with 20 tables, you have to perform:

  • One index lookup on the root table (again, assuming the entity is fetched by id)
  • With a clustered index, we can assume that the values for the root row are in the index
  • 20+ range lookups (hopefully on an index) for the entity's pk value
  • These probably aren't clustered indexes, so the same 20+ data lookups once we figure out what the appropriate child rows are.

So the total for mysql, even assuming that all indexes are in memory (which is harder since there are 20 times more of them) is about 20 range lookups.

These range lookups are likely comprised of random IO — different tables will definitely reside in different spots on disk, and it's possible that different rows in the same range in the same table for an entity might not be contiguous (depending on how the entity has been updated, etc).

So for this example, the final tally is about 20 times more IO with MySQL per logical access, compared to MongoDB.

This is how MongoDB can boost performance in some use cases.

How to change navigation bar color in iOS 7 or 6?

The background color property is ignored on a UINavigationBar, so if you want to adjust the look and feel you either have to use the tintColor or call some of the other methods listed under "Customizing the Bar Appearance" of the UINavigationBar class reference (like setBackgroundImage:forBarMetrics:).

Be aware that the tintColor property works differently in iOS 7, so if you want a consistent look between iOS 7 and prior version using a background image might be your best bet. It's also worth mentioning that you can't configure the background image in the Storyboard, you'll have to create an IBOutlet to your UINavigationBar and change it in viewDidLoad or some other appropriate place.

Wait until ActiveWorkbook.RefreshAll finishes - VBA

I was having this same problem, and tried all the above solutions with no success. I finally solved the problem by deleting the entire query and creating a new one.

The new one had the exact same settings as the one that didn't work (literally the same query definition as I simply copied the old one).

I have no idea why this solved the problem, but it did.

Test if a command outputs an empty string

sometimes "something" may come not to stdout but to the stderr of the testing application, so here is the fix working more universal way:

if [[ $(partprobe ${1} 2>&1 | wc -c) -ne 0 ]]; then
    echo "require fixing GPT parititioning"
else
    echo "no GPT fix necessary"
fi

Show/Hide Table Rows using Javascript classes

Well one way to do it would be to just put a class on the "parent" rows and remove all the ids and inline onclick attributes:

<table id="products">
    <thead>
    <tr>
        <th>Product</th>
        <th>Price</th>
        <th>Destination</th>
        <th>Updated on</th>
    </tr>
    </thead>
    <tbody>
    <tr class="parent">
        <td>Oranges</td>
        <td>100</td>
        <td><a href="#">+ On Store</a></td>
        <td>22/10</td>
    </tr>
    <tr>
        <td></td>
        <td>120</td>
        <td>City 1</td>
        <td>22/10</td>
    </tr>
    <tr>
        <td></td>
        <td>140</td>
        <td>City 2</td>
        <td>22/10</td>
    </tr>
    ...etc.
    </tbody>
</table>

And then have some CSS that hides all non-parents:

tbody tr {
    display : none;          // default is hidden
}
tr.parent {
    display : table-row;     // parents are shown
}
tr.open {
    display : table-row;     // class to be given to "open" child rows
}

That greatly simplifies your html. Note that I've added <thead> and <tbody> to your markup to make it easy to hide data rows and ignore heading rows.

With jQuery you can then simply do this:

// when an anchor in the table is clicked
$("#products").on("click","a",function(e) {
    // prevent default behaviour
    e.preventDefault();
    // find all the following TR elements up to the next "parent"
    // and toggle their "open" class
    $(this).closest("tr").nextUntil(".parent").toggleClass("open");
});

Demo: http://jsfiddle.net/CBLWS/1/

Or, to implement something like that in plain JavaScript, perhaps something like the following:

document.getElementById("products").addEventListener("click", function(e) {
    // if clicked item is an anchor
    if (e.target.tagName === "A") {
        e.preventDefault();
        // get reference to anchor's parent TR
        var row = e.target.parentNode.parentNode;
        // loop through all of the following TRs until the next parent is found
        while ((row = nextTr(row)) && !/\bparent\b/.test(row.className))
            toggle_it(row);
    }
});

function nextTr(row) {
    // find next sibling that is an element (skip text nodes, etc.)
    while ((row = row.nextSibling) && row.nodeType != 1);
    return row;
}

function toggle_it(item){ 
     if (/\bopen\b/.test(item.className))       // if item already has the class
         item.className = item.className.replace(/\bopen\b/," "); // remove it
     else                                       // otherwise
         item.className += " open";             // add it
}

Demo: http://jsfiddle.net/CBLWS/

Either way, put the JavaScript in a <script> element that is at the end of the body, so that it runs after the table has been parsed.

How do you align left / right a div without using float?

No need to add extra elements. While flexbox uses very non-intuitive property names if you know what it can do you'll find yourself using it quite often.

<div style="display: flex; justify-content: space-between;">
<span>Item Left</span>
<span>Item Right</span>
</div>

Plan on needing this often?

.align_between {display: flex; justify-content: space-between;}

I see other people using secondary words in the primary position which makes a mess of information hierarchy. If align is the primary task and right, left, and/or between are the secondary the class should be .align_outer, not .outer_align as it will make sense as you vertically scan your code:

.align_between {}
.align_left {}
.align_outer {}
.align_right {}

Good habits over time will allow you to get to bed sooner than later.

Loop through Map in Groovy?

Another option:

def map = ['a':1, 'b':2, 'c':3]
map.each{
  println it.key +" "+ it.value
}

How do I run a VBScript in 32-bit mode on a 64-bit machine?

If you have control over running the cscript executable then run the X:\windows\syswow64\cscript.exe version which is the 32bit implementation.

Android ListView Divider

I had the same issue. However making the view 1px didn't seem to work on my original Nexus 7. I noticed that the screen density was 213 which is less than the 240 used in xhdpi. So it was thinking the device was an mdpi density.

My solution was to make it so the dimens folder had a dividerHeight parameter. I set it to 2dp in the values-mdpi folder but 1dp in the values-hdpi etc folders.

Global variables in Java

There are no global variables in Java, but there are global classes with public fields. You can use static import feature of java 5 to make it look almost like global variables.

Where is my m2 folder on Mac OS X Mavericks

If you have used brew to install maven, create .m2 directory and then copy settings.xml in .m2 directory.

mkdir ~/.m2
cp /usr/local/Cellar/maven32/3.2.5/libexec/conf/settings.xml ~/.m2

You may need to change the maven version in the path, mine is 3.2.5

ValueError: invalid literal for int () with base 10

I was getting similar errors, turns out that the dataset had blank values which python could not convert to integer.

InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately

If you are not able to upgrade your Python version to 2.7.9, and want to suppress warnings,

you can downgrade your 'requests' version to 2.5.3:

pip install requests==2.5.3

Bugfix disclosure / Warning introduced in 2.6.0

Change Bootstrap tooltip color

You can use this to solve your problem. I checked it in my project and it works fine.

<a class="btn btn-sm btn-success media-tooltip" href="#" data-toggle="tooltip" data-placement="bottom" title="Download Now">Download Now</a>
    .media-tooltip + .tooltip .tooltip-inner {
        font-size: 14px; 
        font-weight: 700;
        color: rgb( 37, 207, 187 ); 
        border-width: 1px;
        border-color: rgb( 37, 207, 187 );
        border-style: solid;
        background-color: rgb( 219, 242, 239 );
        padding: 10px;
        border-radius: 0;
    } 
    .media-tooltip + .tooltip > .tooltip-arrow{display: none;}
    .media-tooltip + .tooltip .tooltip-inner:after, .media-tooltip + .tooltip .tooltip-inner:before {
         bottom: 89%;
         left: 50%;
         border: solid transparent;
         content: " ";
         height: 0;
         width: 0;
         position: absolute;
         pointer-events: none;
    }

    .media-tooltip + .tooltip .tooltip-inner:after {
        border-color: rgba(219, 242, 239, 0);
        border-bottom-color: #dbf2ef;
        border-width: 10px;
        margin-left: -10px;
    }
    .media-tooltip + .tooltip .tooltip-inner:before {
        border-color: rgba(37, 207, 187, 0);
        border-bottom-color: #25cfbb;
        border-width: 11px;
        margin-left: -11px;
    }

Process with an ID #### is not running in visual studio professional 2013 update 3

It looks like there are many solutions that work and some that don't...

My issue kept surfacing after a few test iterations. Yes restarting the PC and/or VS would resolve the issue...but temporarily.

My solution was to undo a security change I had enabled a couple days earlier to Controlled folder access under Ransomware protection.

I undid this change by:
(right click Start) Setting->Update & Security->Windows Security->Virus & threat protection-> Virus & threat protection settings->Manage settings

Under Controlled folder access Click->Manage Controlled folder access (this is also the Ransomware protection screen)

Turn Controlled folder access off.

This was 100% the issue for me as I was able to run my test without restarting VS.

Why use a ReentrantLock if one can use synchronized(this)?

ReentrantReadWriteLock is a specialized lock whereas synchronized(this) is a general purpose lock. They are similar but not quite the same.

You are right in that you could use synchronized(this) instead of ReentrantReadWriteLock but the opposite is not always true.

If you'd like to better understand what makes ReentrantReadWriteLock special look up some information about producer-consumer thread synchronization.

In general you can remember that whole-method synchronization and general purpose synchronization (using the synchronized keyword) can be used in most applications without thinking too much about the semantics of the synchronization but if you need to squeeze performance out of your code you may need to explore other more fine-grained, or special-purpose synchronization mechanisms.

By the way, using synchronized(this) - and in general locking using a public class instance - can be problematic because it opens up your code to potential dead-locks because somebody else not knowingly might try to lock against your object somewhere else in the program.

Get Request and Session Parameters and Attributes from JSF pages

You can also use a tool like OcpSoft's PrettyFaces to inject dynamic parameter values directly into JSF Beans.

how to evenly distribute elements in a div next to each other?

_x000D_
_x000D_
.container {_x000D_
  padding: 10px;_x000D_
}_x000D_
.parent {_x000D_
  width: 100%;_x000D_
  background: #7b7b7b;_x000D_
  display: flex;_x000D_
  justify-content: space-between;_x000D_
  height: 4px;_x000D_
}_x000D_
.child {_x000D_
  color: #fff;_x000D_
  background: green;_x000D_
  padding: 10px 10px;_x000D_
  border-radius: 50%;_x000D_
  position: relative;_x000D_
  top: -8px;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="parent">_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
    <span class="child"></span>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Passing enum or object through an intent (the best solution)

If you really need to, you could serialize an enum as a String, using name() and valueOf(String), as follows:

 class Example implements Parcelable { 
   public enum Foo { BAR, BAZ }

   public Foo fooValue;

   public void writeToParcel(Parcel dest, int flags) {
      parcel.writeString(fooValue == null ? null : fooValue.name());
   }

   public static final Creator<Example> CREATOR = new Creator<Example>() {
     public Example createFromParcel(Parcel source) {        
       Example e = new Example();
       String s = source.readString(); 
       if (s != null) e.fooValue = Foo.valueOf(s);
       return e;
     }
   }
 }

This obviously doesn't work if your enums have mutable state (which they shouldn't, really).

Select unique or distinct values from a list in UNIX shell script

For larger data sets where sorting may not be desirable, you can also use the following perl script:

./yourscript.ksh | perl -ne 'if (!defined $x{$_}) { print $_; $x{$_} = 1; }'

This basically just remembers every line output so that it doesn't output it again.

It has the advantage over the "sort | uniq" solution in that there's no sorting required up front.

How can I get the full/absolute URL (with domain) in Django?

As mentioned in other answers, request.build_absolute_uri() is perfect if you have access to request, and sites framework is great as long as different URLs point to different databases.

However, my use case was slightly different. My staging server and the production server access the same database, but get_current_site both returned the first site in the database. To resolve this, you have to use some kind of environment variable. You can either use 1) an environment variable (something like os.environ.get('SITE_URL', 'localhost:8000')) or 2) different SITE_IDs for different servers AND different settings.py.

Hopefully someone will find this useful!

Java String import

import java.lang.String;

This is an unnecessary import. java.lang classes are always implicitly imported. This means that you do not have to import them manually (explicitly).

How to calculate Date difference in Hive

datediff(to_date(String timestamp), to_date(String timestamp))

For example:

SELECT datediff(to_date('2019-08-03'), to_date('2019-08-01')) <= 2;

How to replace DOM element in place using Javascript?

Given the already proposed options the easiest solution without finding a parent:

var parent = document.createElement("div");
var child = parent.appendChild(document.createElement("a"));
var span = document.createElement("span");

// for IE
if("replaceNode" in child)
  child.replaceNode(span);

// for other browsers
if("replaceWith" in child)
  child.replaceWith(span);

console.log(parent.outerHTML);

Need to get current timestamp in Java

java.time

As of Java 8+ you can use the java.time package. Specifically, use DateTimeFormatterBuilder and DateTimeFormatter to format the patterns and literals.

DateTimeFormatter formatter = new DateTimeFormatterBuilder()
        .appendPattern("MM").appendLiteral("/")
        .appendPattern("dd").appendLiteral("/")
        .appendPattern("yyyy").appendLiteral(" ")
        .appendPattern("hh").appendLiteral(":")
        .appendPattern("mm").appendLiteral(":")
        .appendPattern("ss").appendLiteral(" ")
        .appendPattern("a")
        .toFormatter();
System.out.println(LocalDateTime.now().format(formatter));

The output ...

06/22/2015 11:59:14 AM

Or if you want different time zone

// system default
System.out.println(formatter.withZone(ZoneId.systemDefault()).format(Instant.now()));
// Chicago
System.out.println(formatter.withZone(ZoneId.of("America/Chicago")).format(Instant.now()));
// Kathmandu
System.out.println(formatter.withZone(ZoneId.of("Asia/Kathmandu")).format(Instant.now()));

The output ...

06/22/2015 12:38:42 PM
06/22/2015 02:08:42 AM
06/22/2015 12:53:42 PM

How do I calculate r-squared using Python and Numpy?

I have been using this successfully, where x and y are array-like.

def rsquared(x, y):
    """ Return R^2 where x and y are array-like."""

    slope, intercept, r_value, p_value, std_err = scipy.stats.linregress(x, y)
    return r_value**2

Error: getaddrinfo ENOTFOUND in nodejs for get call

var http = require('http');

  var options = {     
      host: 'localhost',
      port: 80,
      path: '/broadcast'
    };

  var requestLoop = setInterval(function(){

      http.get (options, function (resp) {
        resp.on('data', function (d) {
          console.log ('data!', d.toString());
        });
        resp.on('end', function (d) {
           console.log ('Finished !');
        });
      }).on('error', function (e) {
          console.log ('error:', e);
      });
  }, 10000);

var dns = require('dns'), cache = {};
dns._lookup = dns.lookup;
dns.lookup = function(domain, family, done) {
    if (!done) {
        done = family;
        family = null;
    }

    var key = domain+family;
    if (key in cache) {
        var ip = cache[key],
            ipv = ip.indexOf('.') !== -1 ? 4 : 6;

        return process.nextTick(function() {
            done(null, ip, ipv);
        });
    }

    dns._lookup(domain, family, function(err, ip, ipv) {
        if (err) return done(err);
        cache[key] = ip;
        done(null, ip, ipv);
    });
};

// Works fine (100%)

How do I check if an HTML element is empty using jQuery?

JavaScript

var el= document.querySelector('body'); 
console.log(el);
console.log('Empty : '+ isEmptyTag(el));
console.log('Having Children : '+ hasChildren(el));


function isEmptyTag(tag) { 
    return (tag.innerHTML.trim() === '') ? true : false ;
}
function hasChildren(tag) {
    //return (tag.childElementCount !== 0) ? true : false ; // Not For IE
    //return (tag.childNodes.length !== 0) ? true : false ; // Including Comments
    return (tag.children.length !== 0) ? true : false ; // Only Elements
}

try using any of this!

document.getElementsByTagName('div')[0];
document.getElementsByClassName('topbar')[0];

document.querySelectorAll('div')[0];
document.querySelector('div'); // gets the first element.
?

LINQ Where with AND OR condition

from item in db.vw_Dropship_OrderItems
    where (listStatus != null ? listStatus.Contains(item.StatusCode) : true) &&
    (listMerchants != null ? listMerchants.Contains(item.MerchantId) : true)
    select item;

Might give strange behavior if both listMerchants and listStatus are both null.

Get the last element of a std::string

You probably want to check the length of the string first and do something like this:

if (!myStr.empty())
{
    char lastChar = *myStr.rbegin();
}

OWIN Security - How to Implement OAuth2 Refresh Tokens

I don't think that you should be using an array to maintain tokens. Neither you need a guid as a token.

You can easily use context.SerializeTicket().

See my below code.

public class RefreshTokenProvider : IAuthenticationTokenProvider
{
    public async Task CreateAsync(AuthenticationTokenCreateContext context)
    {
        Create(context);
    }

    public async Task ReceiveAsync(AuthenticationTokenReceiveContext context)
    {
        Receive(context);
    }

    public void Create(AuthenticationTokenCreateContext context)
    {
        object inputs;
        context.OwinContext.Environment.TryGetValue("Microsoft.Owin.Form#collection", out inputs);

        var grantType = ((FormCollection)inputs)?.GetValues("grant_type");

        var grant = grantType.FirstOrDefault();

        if (grant == null || grant.Equals("refresh_token")) return;

        context.Ticket.Properties.ExpiresUtc = DateTime.UtcNow.AddDays(Constants.RefreshTokenExpiryInDays);

        context.SetToken(context.SerializeTicket());
    }

    public void Receive(AuthenticationTokenReceiveContext context)
    {
        context.DeserializeTicket(context.Token);

        if (context.Ticket == null)
        {
            context.Response.StatusCode = 400;
            context.Response.ContentType = "application/json";
            context.Response.ReasonPhrase = "invalid token";
            return;
        }

        if (context.Ticket.Properties.ExpiresUtc <= DateTime.UtcNow)
        {
            context.Response.StatusCode = 401;
            context.Response.ContentType = "application/json";
            context.Response.ReasonPhrase = "unauthorized";
            return;
        }

        context.Ticket.Properties.ExpiresUtc = DateTime.UtcNow.AddDays(Constants.RefreshTokenExpiryInDays);
        context.SetTicket(context.Ticket);
    }
}

Add spaces between the characters of a string in Java?

I am creating a java method for this purpose with dynamic character

public String insertSpace(String myString,int indexno,char myChar){
    myString=myString.substring(0, indexno)+ myChar+myString.substring(indexno);
    System.out.println(myString);
    return myString;
}

Iteration ng-repeat only X times in AngularJs

This is the simplest workaround I could think of.

<span ng-repeat="n in [].constructor(5) track by $index">
{{$index}}
</span>

Here's a Plunker example.

PreparedStatement with Statement.RETURN_GENERATED_KEYS

You mean something like this?

long key = -1L;

PreparedStatement preparedStatement = connection.prepareStatement(YOUR_SQL_HERE, PreparedStatement.RETURN_GENERATED_KEYS);
preparedStatement.setXXX(index, VALUE);
preparedStatement.executeUpdate();

ResultSet rs = preparedStatement.getGeneratedKeys();

if (rs.next()) {
    key = rs.getLong(1);
}

javascript: pause setTimeout();

function delay (ms)   {  return new Promise(resolve => setTimeout(resolve, s));  }

"async" working demo at: site zarsoft.info

Setting selected option in laravel form

If you have an Eloquent Relationship between your models you can do something like that:

@foreach ($ships as  $ship)
<select name="data[]" class="form-control" multiple>
    @foreach ($goods_containers as  $container)
        <option value="{{ $container->id }}"
                @if ($ship->containers->contains('container_id',$container->id ) ))
                selected="selected"
                @endif
        >{{ $container->number}}</option>
    @endforeach
</select>
@endforeach

How to get the children of the $(this) selector?

You can find all img element of parent div like below

$(this).find('img') or $(this).children('img')

If you want specific img element you can write like this

$(this).children('img:nth(n)')  
// where n is the child place in parent list start from 0 onwards

Your div contain only one img element. So for this below is right

 $(this).find("img").attr("alt")
                  OR
  $(this).children("img").attr("alt")

But if your div contain more img element like below

<div class="mydiv">
    <img src="test.png" alt="3">
    <img src="test.png" alt="4">
</div>

then you can't use upper code to find alt value of second img element. So you can try this:

 $(this).find("img:last-child").attr("alt")
                   OR
 $(this).children("img:last-child").attr("alt")

This example shows a general idea that how you can find actual object within parent object. You can use classes to differentiate your child object. That is easy and fun. i.e.

<div class="mydiv">
    <img class='first' src="test.png" alt="3">
    <img class='second' src="test.png" alt="4">
</div>

You can do this as below :

 $(this).find(".first").attr("alt")

and more specific as:

 $(this).find("img.first").attr("alt")

You can use find or children as above code. For more visit Children http://api.jquery.com/children/ and Find http://api.jquery.com/find/. See example http://jsfiddle.net/lalitjs/Nx8a6/

How to delete a whole folder and content?

public static void deleteDirectory( File dir )
{

    if ( dir.isDirectory() )
    {
        String [] children = dir.list();
        for ( int i = 0 ; i < children.length ; i ++ )
        {
         File child =    new File( dir , children[i] );
         if(child.isDirectory()){
             deleteDirectory( child );
             child.delete();
         }else{
             child.delete();

         }
        }
        dir.delete();
    }
}

Efficiently replace all accented characters in a string?

If you're looking specifically for a way to convert accented characters to non-accented characters, rather than a way to sort accented characters, with a little finagling, the String.localeCompare function can be manipulated to find the basic latin characters that match the extended ones. For example, you might want to produce a human friendly url slug from a page title. If so, you can do something like this:

_x000D_
_x000D_
var baseChars = [];_x000D_
for (var i = 97; i < 97 + 26; i++) {_x000D_
  baseChars.push(String.fromCharCode(i));_x000D_
}_x000D_
_x000D_
//if needed, handle fancy compound characters_x000D_
baseChars = baseChars.concat('ss,aa,ae,ao,au,av,ay,dz,hv,lj,nj,oi,ou,oo,tz,vy'.split(','));_x000D_
_x000D_
function isUpperCase(c) { return c !== c.toLocaleLowerCase() }_x000D_
_x000D_
function toBaseChar(c, opts) {_x000D_
  opts = opts || {};_x000D_
  //if (!('nonAlphaChar' in opts)) opts.nonAlphaChar = '';_x000D_
  //if (!('noMatchChar' in opts)) opts.noMatchChar = '';_x000D_
  if (!('locale' in opts)) opts.locale = 'en';_x000D_
_x000D_
  var cOpts = {sensitivity: 'base'};_x000D_
_x000D_
  //exit early for any non-alphabetical character_x000D_
  if (c.localeCompare('9', opts.locale, cOpts) <= 0) return opts.nonAlphaChar === undefined ? c : opts.nonAlphaChar;_x000D_
_x000D_
  for (var i = 0; i < baseChars.length; i++) {_x000D_
    var baseChar = baseChars[i];_x000D_
_x000D_
    var comp = c.localeCompare(baseChar, opts.locale, cOpts);_x000D_
    if (comp == 0) return (isUpperCase(c)) ? baseChar.toUpperCase() : baseChar;_x000D_
  }_x000D_
_x000D_
  return opts.noMatchChar === undefined ? c : opts.noMatchChar;_x000D_
}_x000D_
_x000D_
function latinify(str, opts) {_x000D_
  return str.replace(/[^\w\s\d]/g, function(c) {_x000D_
    return toBaseChar(c, opts);_x000D_
  })_x000D_
}_x000D_
_x000D_
// Example:_x000D_
console.log(latinify('Ceština Tsehesenestsestotse Tshiven?a Emigliàn–Rumagnòl Slovenšcina Português Ti?ng Vi?t Straße'))_x000D_
_x000D_
// "Cestina Tsehesenestsestotse Tshivenda Emiglian–Rumagnol Slovenscina Portugues Tieng Viet Strasse"
_x000D_
_x000D_
_x000D_

This should perform quite well, but if further optimization were needed, a binary search could be used with localeCompare as the comparator to locate the base character. Note that case is preserved, and options allow for either preserving, replacing, or removing characters that aren't alphabetical, or do not have matching latin characters they can be replaced with. This implementation is faster and more flexible, and should work with new characters as they are added. The disadvantage is that compound characters like '?' have to be handled specifically, if they need to be supported.

Maximum Length of Command Line String

In Windows 10, it's still 8191 characters...at least on my machine.

It just cuts off any text after 8191 characters. Well, actually, I got 8196 characters, and after 8196, then it just won't let me type any more.

Here's a script that will test how long of a statement you can use. Well, assuming you have gawk/awk installed.

echo rem this is a test of how long of a line that a .cmd script can generate >testbat.bat
gawk 'BEGIN {printf "echo -----";for (i=10;i^<=100000;i +=10) printf "%%06d----",i;print;print "pause";}' >>testbat.bat
testbat.bat

increment date by one month

All presented solutions are not working properly.
strtotime() and DateTime::add or DateTime::modify give sometime invalid results.
Examples:
- 31.08.2019 + 1 month gives 01.10.2019 instead 30.09.2019
- 29.02.2020 + 1 year gives 01.03.2021 instead 28.02.2021
(tested on PHP 5.5, PHP 7.3)

Below is my function based on idea posted by Angelo that solves the problem:

// $time - unix time or date in any format accepted by strtotime() e.g. 2020-02-29  
// $days, $months, $years - values to add
// returns new date in format 2021-02-28
function addTime($time, $days, $months, $years)
{
    // Convert unix time to date format
    if (is_numeric($time))
    $time = date('Y-m-d', $time);

    try
    {
        $date_time = new DateTime($time);
    }
    catch (Exception $e)
    {
        echo $e->getMessage();
        exit;
    }

    if ($days)
    $date_time->add(new DateInterval('P'.$days.'D'));

    // Preserve day number
    if ($months or $years)
    $old_day = $date_time->format('d');

    if ($months)
    $date_time->add(new DateInterval('P'.$months.'M'));

    if ($years)
    $date_time->add(new DateInterval('P'.$years.'Y'));

    // Patch for adding months or years    
    if ($months or $years)
    {
        $new_day = $date_time->format("d");

        // The day is changed - set the last day of the previous month
        if ($old_day != $new_day)
        $date_time->sub(new DateInterval('P'.$new_day.'D'));
    }
    // You can chage returned format here
    return $date_time->format('Y-m-d');
}

Usage examples:

echo addTime('2020-02-29', 0, 0, 1); // add 1 year (result: 2021-02-28)
echo addTime('2019-08-31', 0, 1, 0); // add 1 month (result: 2019-09-30)
echo addTime('2019-03-15', 12, 2, 1); // add 12 days, 2 months, 1 year (result: 2019-09-30)

Using Keras & Tensorflow with AMD GPU

The original question on this post was: How to get Keras and Tensorflow to run with an AMD GPU.

The answer to this question is as followed:

1.) Keras will work if you can make Tensorflow work correctly (optionally within your virtual/conda environment).

2.) To get Tensorflow to work on an AMD GPU, as others have stated, one way this could work is to compile Tensorflow to use OpenCl. To do so read the link below. But for brevity I will summarize the required steps here:

  • You will need AMDs proprietary drivers. These are currently only available on Ubuntu 14.04 (the version before Ubuntu decided to change the way the UI is rendered). Support for Ubuntu 16.04 is at the writing of this post limited to a few GPUs through AMDProDrivers. Readers who want to do deep learning on AMD GPUs should be aware of this!

  • Compiling Tensorflow with OpenCl support also requires you to obtain and install the following prerequisites: OpenCl headers, ComputeCpp.

  • After the prerequisites are fulfilled, configure your build. Note that there are 3 options for compiling Tensorflow: Std Tensorflow (stable), Benoits Steiner's Tensorflow-opencl (developmental), and Luke Iwanski's Tensorflow-opencl (highly experimental) which you can pull from github. Also note that if you decide to build from any of the opencl versions, the question to use opencl will be missing because it is assumed that you are using it. Conversely, this means that if you configure from the standard tensorflow, you will need to select "Yes" when the configure script asks you to use opencl and "NO" for CUDA.

  • Then run tests like so:

    $ bazel test --config=sycl -k --test_timeout 1600 -- //tensorflow/... -//tensorflow/contrib/... -//tensorflow/java/... -//tensorflow /compiler/...

Update: Doing this on my setup takes exceedingly long on my setup. The part that takes long are all the tests running. I am not sure what this means but a lot of my tests are timeing out at 1600 seconds. The duration can probably be shortened at the expense of more tests timeing out. Alternatively, you can just build tensor flow without tests. At the time of this writing, running the tests has taken 2 days already.

Or just build the pip package like so:

bazel build --local_resources 2048,.5,1.0 -c opt --config=sycl //tensorflow/tools/pip_package:build_pip_package

Please actually read the blog post over at Codeplay: Lukas Iwansky posted a comprehensive tutorial post on how to get Tensorflow to work with OpenCl just on March 30th 2017. So this is a very recent post. There are also some details which I did not write about here.

As indicated in the many posts above, little bits of information are spread throughout the interwebs. What Lukas' post adds in terms of value is that all the information was put together into one place which should make setting up Tensforflow and OpenCl a bit less daunting. I will only provide a link here:

https://www.codeplay.com/portal/03-30-17-setting-up-tensorflow-with-opencl-using-sycl

A slightly more complete walk-through has been posted here:

http://deep-beta.co.uk/setting-up-tensorflow-with-opencl-using-sycl/

It differs mainly by explicitly telling the user that he/she needs to:

  • create symlinks to a subfolder
  • and then actually install tensorflow via "python setup.py develop" command.

Note an alternative approach was mentioned above using tensorflow-cl:

https://github.com/hughperkins/tensorflow-cl

I am unable to discern which approach is better at this time though it appears that this approach is less active. Fewer issues are posted, and fewer conversations to resolve those issues are happening. There was a major push last year. Additional pushes have ebbed off since November 2016 although Hugh seems to have pushed some updates a few days ago as of the writing of this post. (Update: If you read some of the documentation readme, this version of tensorflowo now only relies on community support as the main developer is busy with life.)

UPDATE (2017-04-25): I have some notes based on testing tensorflow-opencl below.

  • The future user of this package should note that using opencl means that all the heavy-lifting in terms of computing is shifted to the GPU. I mention this because I was personally thinking that the compute work-load would be shared between my CPU and iGPU. This means that the power of your GPU is very important (specifically, bandwidth, and available VRAM).

Following are some numbers for calculating 1 epoch using the CIFAR10 data set for MY SETUP (A10-7850 with iGPU). Your mileage will almost certainly vary!

  • Tensorflow (via pip install): ~ 1700 s/epoch
  • Tensorflow (w/ SSE + AVX): ~ 1100 s/epoch
  • Tensorflow (w/ opencl & iGPU): ~ 5800 s/epoch

You can see that in this particular case performance is worse. I attribute this to the following factors:

  • The iGPU only has 1GB. This leads to a lot of copying back and forth between CPU and GPU. (Opencl 1.2 does not have the ability to data pass via pointers yet; instead data has to be copied back and forth.)
  • The iGPU only has 512 stream processors (and 32 Gb/s memory bandwidth) which in this case is slower than 4 CPUs using SSE4 + AVX instruction sets.
  • The development of tensorflow-opencl is in it's beginning stages, and a lot of optimizations in SYCL etc. have not been done yet.

If you are using an AMD GPU with more VRAM and more stream processors, you are certain to get much better performance numbers. I would be interested to read what numbers people are achieving to know what's possible.

I will continue to maintain this answer if/when updates get pushed.

3.) An alternative way is currently being hinted at which is using AMD's RocM initiative, and miOpen (cuDNN equivalent) library. These are/will be open-source libraries that enable deep learning. The caveat is that RocM support currently only exists for Linux, and that miOpen has not been released to the wild yet, but Raja (AMD GPU head) has said in an AMA that using the above, it should be possible to do deep learning on AMD GPUs. In fact, support is planned for not only Tensorflow, but also Cafe2, Cafe, Torch7 and MxNet.

making matplotlib scatter plots from dataframes in Python's pandas

Try passing columns of the DataFrame directly to matplotlib, as in the examples below, instead of extracting them as numpy arrays.

df = pd.DataFrame(np.random.randn(10,2), columns=['col1','col2'])
df['col3'] = np.arange(len(df))**2 * 100 + 100

In [5]: df
Out[5]: 
       col1      col2  col3
0 -1.000075 -0.759910   100
1  0.510382  0.972615   200
2  1.872067 -0.731010   500
3  0.131612  1.075142  1000
4  1.497820  0.237024  1700

Vary scatter point size based on another column

plt.scatter(df.col1, df.col2, s=df.col3)
# OR (with pandas 0.13 and up)
df.plot(kind='scatter', x='col1', y='col2', s=df.col3)

enter image description here

Vary scatter point color based on another column

colors = np.where(df.col3 > 300, 'r', 'k')
plt.scatter(df.col1, df.col2, s=120, c=colors)
# OR (with pandas 0.13 and up)
df.plot(kind='scatter', x='col1', y='col2', s=120, c=colors)

enter image description here

Scatter plot with legend

However, the easiest way I've found to create a scatter plot with legend is to call plt.scatter once for each point type.

cond = df.col3 > 300
subset_a = df[cond].dropna()
subset_b = df[~cond].dropna()
plt.scatter(subset_a.col1, subset_a.col2, s=120, c='b', label='col3 > 300')
plt.scatter(subset_b.col1, subset_b.col2, s=60, c='r', label='col3 <= 300') 
plt.legend()

enter image description here

Update

From what I can tell, matplotlib simply skips points with NA x/y coordinates or NA style settings (e.g., color/size). To find points skipped due to NA, try the isnull method: df[df.col3.isnull()]

To split a list of points into many types, take a look at numpy select, which is a vectorized if-then-else implementation and accepts an optional default value. For example:

df['subset'] = np.select([df.col3 < 150, df.col3 < 400, df.col3 < 600],
                         [0, 1, 2], -1)
for color, label in zip('bgrm', [0, 1, 2, -1]):
    subset = df[df.subset == label]
    plt.scatter(subset.col1, subset.col2, s=120, c=color, label=str(label))
plt.legend()

enter image description here

How to use css style in php

Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation semantics (the look and formatting) of a document written in a markup language. more info : http://en.wikipedia.org/wiki/Cascading_Style_Sheets CSS is not a programming language, and does not have the tools that come with a server side language like PHP. However, we can use Server-side languages to generate style sheets.

<html>
<head>
<title>...</title>
<style type="text/css">
table {
margin: 8px;
}

th {
font-family: Arial, Helvetica, sans-serif;
font-size: .7em;
background: #666;
color: #FFF;
padding: 2px 6px;
border-collapse: separate;
border: 1px solid #000;
}

td {
font-family: Arial, Helvetica, sans-serif;
font-size: .7em;
border: 1px solid #DDD;
}
</style>
</head>
<body>
<?php>
echo "<table>";
echo "<tr><th>ID</th><th>hashtag</th></tr>";
while($row = mysql_fetch_row($result))
{
echo "<tr onmouseover=\"hilite(this)\" onmouseout=\"lowlite(this)\"><td>$row[0]</td>                <td>$row[1]</td></tr>\n";
}
echo "</table>";
?>
</body>
</html>

Git merge without auto commit

When there is one commit only in the branch, I usually do

git merge branch_name --ff

Is it possible to create static classes in PHP (like in C#)?

You can have static classes in PHP but they don't call the constructor automatically (if you try and call self::__construct() you'll get an error).

Therefore you'd have to create an initialize() function and call it in each method:

<?php

class Hello
{
    private static $greeting = 'Hello';
    private static $initialized = false;

    private static function initialize()
    {
        if (self::$initialized)
            return;

        self::$greeting .= ' There!';
        self::$initialized = true;
    }

    public static function greet()
    {
        self::initialize();
        echo self::$greeting;
    }
}

Hello::greet(); // Hello There!


?>

Display calendar to pick a date in java

I wrote a DateTextField component.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.JTextField;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.border.LineBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class DateTextField extends JTextField {

    private static String DEFAULT_DATE_FORMAT = "MM/dd/yyyy";
    private static final int DIALOG_WIDTH = 200;
    private static final int DIALOG_HEIGHT = 200;

    private SimpleDateFormat dateFormat;
    private DatePanel datePanel = null;
    private JDialog dateDialog = null;

    public DateTextField() {
        this(new Date());
    }

    public DateTextField(String dateFormatPattern, Date date) {
        this(date);
        DEFAULT_DATE_FORMAT = dateFormatPattern;
    }

    public DateTextField(Date date) {
        setDate(date);
        setEditable(false);
        setCursor(new Cursor(Cursor.HAND_CURSOR));
        addListeners();
    }

    private void addListeners() {
        addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent paramMouseEvent) {
                if (datePanel == null) {
                    datePanel = new DatePanel();
                }
                Point point = getLocationOnScreen();
                point.y = point.y + 30;
                showDateDialog(datePanel, point);
            }
        });
    }

    private void showDateDialog(DatePanel dateChooser, Point position) {
        Frame owner = (Frame) SwingUtilities
                .getWindowAncestor(DateTextField.this);
        if (dateDialog == null || dateDialog.getOwner() != owner) {
            dateDialog = createDateDialog(owner, dateChooser);
        }
        dateDialog.setLocation(getAppropriateLocation(owner, position));
        dateDialog.setVisible(true);
    }

    private JDialog createDateDialog(Frame owner, JPanel contentPanel) {
        JDialog dialog = new JDialog(owner, "Date Selected", true);
        dialog.setUndecorated(true);
        dialog.getContentPane().add(contentPanel, BorderLayout.CENTER);
        dialog.pack();
        dialog.setSize(DIALOG_WIDTH, DIALOG_HEIGHT);
        return dialog;
    }

    private Point getAppropriateLocation(Frame owner, Point position) {
        Point result = new Point(position);
        Point p = owner.getLocation();
        int offsetX = (position.x + DIALOG_WIDTH) - (p.x + owner.getWidth());
        int offsetY = (position.y + DIALOG_HEIGHT) - (p.y + owner.getHeight());

        if (offsetX > 0) {
            result.x -= offsetX;
        }

        if (offsetY > 0) {
            result.y -= offsetY;
        }

        return result;
    }

    private SimpleDateFormat getDefaultDateFormat() {
        if (dateFormat == null) {
            dateFormat = new SimpleDateFormat(DEFAULT_DATE_FORMAT);
        }
        return dateFormat;
    }

    public void setText(Date date) {
        setDate(date);
    }

    public void setDate(Date date) {
        super.setText(getDefaultDateFormat().format(date));
    }

    public Date getDate() {
        try {
            return getDefaultDateFormat().parse(getText());
        } catch (ParseException e) {
            return new Date();
        }
    }

    private class DatePanel extends JPanel implements ChangeListener {
        int startYear = 1980;
        int lastYear = 2050;

        Color backGroundColor = Color.gray;
        Color palletTableColor = Color.white;
        Color todayBackColor = Color.orange;
        Color weekFontColor = Color.blue;
        Color dateFontColor = Color.black;
        Color weekendFontColor = Color.red;

        Color controlLineColor = Color.pink;
        Color controlTextColor = Color.white;

        JSpinner yearSpin;
        JSpinner monthSpin;
        JButton[][] daysButton = new JButton[6][7];

        DatePanel() {
            setLayout(new BorderLayout());
            setBorder(new LineBorder(backGroundColor, 2));
            setBackground(backGroundColor);

            JPanel topYearAndMonth = createYearAndMonthPanal();
            add(topYearAndMonth, BorderLayout.NORTH);
            JPanel centerWeekAndDay = createWeekAndDayPanal();
            add(centerWeekAndDay, BorderLayout.CENTER);

            reflushWeekAndDay();
        }

        private JPanel createYearAndMonthPanal() {
            Calendar cal = getCalendar();
            int currentYear = cal.get(Calendar.YEAR);
            int currentMonth = cal.get(Calendar.MONTH) + 1;

            JPanel panel = new JPanel();
            panel.setLayout(new FlowLayout());
            panel.setBackground(controlLineColor);

            yearSpin = new JSpinner(new SpinnerNumberModel(currentYear,
                    startYear, lastYear, 1));
            yearSpin.setPreferredSize(new Dimension(56, 20));
            yearSpin.setName("Year");
            yearSpin.setEditor(new JSpinner.NumberEditor(yearSpin, "####"));
            yearSpin.addChangeListener(this);
            panel.add(yearSpin);

            JLabel yearLabel = new JLabel("Year");
            yearLabel.setForeground(controlTextColor);
            panel.add(yearLabel);

            monthSpin = new JSpinner(new SpinnerNumberModel(currentMonth, 1,
                    12, 1));
            monthSpin.setPreferredSize(new Dimension(35, 20));
            monthSpin.setName("Month");
            monthSpin.addChangeListener(this);
            panel.add(monthSpin);

            JLabel monthLabel = new JLabel("Month");
            monthLabel.setForeground(controlTextColor);
            panel.add(monthLabel);

            return panel;
        }

        private JPanel createWeekAndDayPanal() {
            String colname[] = { "S", "M", "T", "W", "T", "F", "S" };
            JPanel panel = new JPanel();
            panel.setFont(new Font("Arial", Font.PLAIN, 10));
            panel.setLayout(new GridLayout(7, 7));
            panel.setBackground(Color.white);

            for (int i = 0; i < 7; i++) {
                JLabel cell = new JLabel(colname[i]);
                cell.setHorizontalAlignment(JLabel.RIGHT);
                if (i == 0 || i == 6) {
                    cell.setForeground(weekendFontColor);
                } else {
                    cell.setForeground(weekFontColor);
                }
                panel.add(cell);
            }

            int actionCommandId = 0;
            for (int i = 0; i < 6; i++)
                for (int j = 0; j < 7; j++) {
                    JButton numBtn = new JButton();
                    numBtn.setBorder(null);
                    numBtn.setHorizontalAlignment(SwingConstants.RIGHT);
                    numBtn.setActionCommand(String
                            .valueOf(actionCommandId));
                    numBtn.setBackground(palletTableColor);
                    numBtn.setForeground(dateFontColor);
                    numBtn.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent event) {
                            JButton source = (JButton) event.getSource();
                            if (source.getText().length() == 0) {
                                return;
                            }
                            dayColorUpdate(true);
                            source.setForeground(todayBackColor);
                            int newDay = Integer.parseInt(source.getText());
                            Calendar cal = getCalendar();
                            cal.set(Calendar.DAY_OF_MONTH, newDay);
                            setDate(cal.getTime());

                            dateDialog.setVisible(false);
                        }
                    });

                    if (j == 0 || j == 6)
                        numBtn.setForeground(weekendFontColor);
                    else
                        numBtn.setForeground(dateFontColor);
                    daysButton[i][j] = numBtn;
                    panel.add(numBtn);
                    actionCommandId++;
                }

            return panel;
        }

        private Calendar getCalendar() {
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(getDate());
            return calendar;
        }

        private int getSelectedYear() {
            return ((Integer) yearSpin.getValue()).intValue();
        }

        private int getSelectedMonth() {
            return ((Integer) monthSpin.getValue()).intValue();
        }

        private void dayColorUpdate(boolean isOldDay) {
            Calendar cal = getCalendar();
            int day = cal.get(Calendar.DAY_OF_MONTH);
            cal.set(Calendar.DAY_OF_MONTH, 1);
            int actionCommandId = day - 2 + cal.get(Calendar.DAY_OF_WEEK);
            int i = actionCommandId / 7;
            int j = actionCommandId % 7;
            if (isOldDay) {
                daysButton[i][j].setForeground(dateFontColor);
            } else {
                daysButton[i][j].setForeground(todayBackColor);
            }
        }

        private void reflushWeekAndDay() {
            Calendar cal = getCalendar();
            cal.set(Calendar.DAY_OF_MONTH, 1);
            int maxDayNo = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
            int dayNo = 2 - cal.get(Calendar.DAY_OF_WEEK);
            for (int i = 0; i < 6; i++) {
                for (int j = 0; j < 7; j++) {
                    String s = "";
                    if (dayNo >= 1 && dayNo <= maxDayNo) {
                        s = String.valueOf(dayNo);
                    }
                    daysButton[i][j].setText(s);
                    dayNo++;
                }
            }
            dayColorUpdate(false);
        }

        public void stateChanged(ChangeEvent e) {
            dayColorUpdate(true);

            JSpinner source = (JSpinner) e.getSource();
            Calendar cal = getCalendar();
            if (source.getName().equals("Year")) {
                cal.set(Calendar.YEAR, getSelectedYear());
            } else {
                cal.set(Calendar.MONTH, getSelectedMonth() - 1);
            }
            setDate(cal.getTime());
            reflushWeekAndDay();
        }
    }
}

Read .mat files in Python

There is a nice package called mat4py which can easily be installed using

pip install mat4py

It is straightforward to use (from the website):

Load data from a MAT-file

The function loadmat loads all variables stored in the MAT-file into a simple Python data structure, using only Python’s dict and list objects. Numeric and cell arrays are converted to row-ordered nested lists. Arrays are squeezed to eliminate arrays with only one element. The resulting data structure is composed of simple types that are compatible with the JSON format.

Example: Load a MAT-file into a Python data structure:

from mat4py import loadmat

data = loadmat('datafile.mat')

The variable data is a dict with the variables and values contained in the MAT-file.

Save a Python data structure to a MAT-file

Python data can be saved to a MAT-file, with the function savemat. Data has to be structured in the same way as for loadmat, i.e. it should be composed of simple data types, like dict, list, str, int, and float.

Example: Save a Python data structure to a MAT-file:

from mat4py import savemat

savemat('datafile.mat', data)

The parameter data shall be a dict with the variables.

How to properly make a http web GET request

var request = (HttpWebRequest)WebRequest.Create("sendrequesturl");
var response = (HttpWebResponse)request.GetResponse();
string responseString;
using (var stream = response.GetResponseStream())
{
    using (var reader = new StreamReader(stream))
    {
        responseString = reader.ReadToEnd();
    }
}

PL/SQL ORA-01422: exact fetch returns more than requested number of rows

It can also be due to a duplicate entry in any of the tables that are used.

Use CSS to automatically add 'required field' asterisk to form inputs

You can achieve the desired result by encapsulating the HTML code in a div tag which contains the "required' class followed by the "form-group" class. *however this works only if you have Bootstrap.

<div class="form-group required">
    <div class="required">
        <label>Name:</label>
        <input type="text">
    </div>
  <div>

Android Studio: Where is the Compiler Error Output Window?

I am building on what Jorge recommended. Goto File->Settings->compiler.

Here you will see a field to add compiler options where you plug in --stacktrace

Create Excel files from C# without office

There are a handful of options:

  • NPOI - Which is free and open source.
  • Aspose - Is definitely not free but robust.
  • Spreadsheet ML - Basically XML for creating spreadsheets.

Using the Interop will require that the Excel be installed on the machine from which it is running. In a server side solution, this will be awful. Instead, you should use a tool like the ones above that lets you build an Excel file without Excel being installed.

If the user does not have Excel but has a tool that will read Excel (like Open Office), then obviously they will be able to open it. Microsoft has a free Excel viewer available for those users that do not have Excel.

If using maven, usually you put log4j.properties under java or resources?

The resources used for initializing the project are preferably put in src/main/resources folder. To enable loading of these resources during the build, one can simply add entries in the pom.xml in maven project as a build resource

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering> 
        </resource>
    </resources>
</build> 

Other .properties files can also be kept in this folder used for initialization. Filtering is set true if you want to have some variables in the properties files of resources folder and populate them from the profile filters properties files, which are kept in src/main/filters which is set as profiles but it is a different use case altogether. For now, you can ignore them.

This is a great resource maven resource plugins, it's useful, just browse through other sections too.

How to "Open" and "Save" using java

I would suggest looking into javax.swing.JFileChooser

Here is a site with some examples in using as both 'Open' and 'Save'. http://www.java2s.com/Code/Java/Swing-JFC/DemonstrationofFiledialogboxes.htm

This will be much less work than implementing for yourself.

How to create an Explorer-like folder browser control?

It's not as easy as it seems to implement a control like that. Explorer works with shell items, not filesystem items (ex: the control panel, the printers folder, and so on). If you need to implement it i suggest to have a look at the Windows shell functions at http://msdn.microsoft.com/en-us/library/bb776426(VS.85).aspx.

How to debug an apache virtual host configuration?

I recently had some issues with a VirtualHost. I used a2ensite to enable a host but before running a restart (which would kill the server on fail) I ran

apache2ctl -S

Which gives you some info about what's going on with your virtual hosts. It's not perfect, but it helps.

Easiest way to convert month name to month number in JS ? (Jan = 01)

Another way;

alert( "JanFebMarAprMayJunJulAugSepOctNovDec".indexOf("Jun") / 3 + 1 );

set option "selected" attribute from dynamic created option

The ideas on this page were helpful, yet as ever my scenario was different. So, in modal bootstrap / express node js / aws beanstalk, this worked for me:

var modal = $(this);
modal.find(".modal-body select#cJourney").val(vcJourney).attr("selected","selected");

Where my select ID = "cJourney" and the drop down value was stored in variable: vcJourney

how to git commit a whole folder?

You don't "commit the folder" - you add the folder, as you have done, and then simply commit all changes. The command should be:

git add foldername
git commit -m "commit operation"

Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE] even if app appears to not be installed

Signature Mismatch your Previous Present APP and new APK

So Please uninstall the previous app and gradlew clean and again install apk

react-native run-android

react-native run-ios

Gradle Build Android Project "Could not resolve all dependencies" error

Add this to your gradle:

allprojects {
    buildscript {
        repositories {
            maven {
                url "https://dl.bintray.com/android/android-tools"
            }
        }
    }
...
}

Git - Ignore files during merge

I got over this issue by using git merge command with the --no-commit option and then explicitly removed the staged file and ignore the changes to the file. E.g.: say I want to ignore any changes to myfile.txt I proceed as follows:

git merge --no-ff --no-commit <merge-branch>
git reset HEAD myfile.txt
git checkout -- myfile.txt
git commit -m "merged <merge-branch>"

You can put statements 2 & 3 in a for loop, if you have a list of files to skip.

Postgresql Windows, is there a default password?

Try this:

Open PgAdmin -> Files -> Open pgpass.conf

You would get the path of pgpass.conf at the bottom of the window. Go to that location and open this file, you can find your password there.

Reference

If the above does not work, you may consider trying this:

 1. edit pg_hba.conf to allow trust authorization temporarily
 2. Reload the config file (pg_ctl reload)
 3. Connect and issue ALTER ROLE / PASSWORD to set the new password
 4. edit pg_hba.conf again and restore the previous settings
 5. Reload the config file again

How to print GETDATE() in SQL Server with milliseconds in time?

If your SQL Server version supports the function FORMAT you could do it like this:

select format(getdate(), 'yyyy-MM-dd HH:mm:ss.fff')

How can I download a file from a URL and save it in Rails?

If you're using PaperClip, downloading from a URL is now handled automatically.

Assuming you've got something like:

class MyModel < ActiveRecord::Base
  has_attached_file :image, ...
end

On your model, just specify the image as a URL, something like this (written in deliberate longhand):

@my_model = MyModel.new
image_url = params[:image_url]
@my_model.image = URI.parse(image_url)

You'll probably want to put this in a method in your model. This will also work just fine on Heroku's temporary filesystem.

Paperclip will take it from there.

source: paperclip documentation

What is INSTALL_PARSE_FAILED_NO_CERTIFICATES error?

I encountered this issue in the JetBrains Rider IDE.

Full Error

INSTALL_PARSE_FAILED_NO_CERTIFICATES: Failed to collect certificates from /data/app/vmdl1252907876.tmp/base.apk: Attempt to get length of null array

The problem was a result of using JDK8. Switching to JDK11 solved the issue.

enter image description here

How do I create a unique ID in Java?

This adds a bit more randomness to the UUID generation but ensures each generated id is the same length

import org.apache.commons.codec.digest.DigestUtils;
import java.util.UUID;

public String createSalt() {
    String ts = String.valueOf(System.currentTimeMillis());
    String rand = UUID.randomUUID().toString();
    return DigestUtils.sha1Hex(ts + rand);
}

Finding and removing non ascii characters from an Oracle Varchar2

I had a similar issue and blogged about it here. I started with the regular expression for alpha numerics, then added in the few basic punctuation characters I liked:

select dump(a,1016), a, b
from
 (select regexp_replace(COLUMN,'[[:alnum:]/''%()> -.:=;[]','') a,
         COLUMN b
  from TABLE)
where a is not null
order by a;

I used dump with the 1016 variant to give out the hex characters I wanted to replace which I could then user in a utl_raw.cast_to_varchar2.

Missing artifact com.oracle:ojdbc6:jar:11.2.0 in pom.xml

I had the same issue. Jenkins's build was falling because of this error..after long hours troubleshooting.

Link to download ojdbc as per your requirement - https://www.oracle.com/database/technologies/maven-central-guide.html

I have downloaded in my maven/bin location and executed the below command.

mvn install:install-file -Dfile=ojdbc8-12.2.0.1.jar -DgroupId=com.oracle -DartifactId=ojdbc8 -Dversion=12.2.0.1 -Dpackaging=jar

POM.xml

<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc8</artifactId>
<version>12.2.0.1</version>
</dependency>

Calculating powers of integers

A simple (no checks for overflow or for validity of arguments) implementation for the repeated-squaring algorithm for computing the power:

/** Compute a**p, assume result fits in a 32-bit signed integer */ 
int pow(int a, int p)
{
    int res = 1;
    int i1 = 31 - Integer.numberOfLeadingZeros(p); // highest bit index
    for (int i = i1; i >= 0; --i) {
        res *= res;
        if ((p & (1<<i)) > 0)
            res *= a;
    }
    return res;
}

The time complexity is logarithmic to exponent p (i.e. linear to the number of bits required to represent p).

Making a <button> that's a link in HTML

<a href="#"><button>Link Text</button></a>

You asked for a link that looks like a button, so use a link and a button :-) This will preserve default browser button styling. The button by itself does nothing, but clicking it activates its parent link.

Demo:

_x000D_
_x000D_
<a href="http://stackoverflow.com"><button>Link Text</button></a>
_x000D_
_x000D_
_x000D_

Is there a simple way to increment a datetime object one month in Python?

Question: Is there a simple way to do this in the current release of Python?

Answer: There is no simple (direct) way to do this in the current release of Python.

Reference: Please refer to docs.python.org/2/library/datetime.html, section 8.1.2. timedelta Objects. As we may understand from that, we cannot increment month directly since it is not a uniform time unit.

Plus: If you want first day -> first day and last day -> last day mapping you should handle that separately for different months.

Common elements comparison between 2 lists

I compared each of method that each answer mentioned. At this moment I use python 3.6.3 for this implementation. This is the code that I have used:

import time
import random
from decimal import Decimal


def method1():
    common_elements = [x for x in li1_temp if x in li2_temp]
     print(len(common_elements))


def method2():
    common_elements = (x for x in li1_temp if x in li2_temp)
    print(len(list(common_elements)))


def method3():
    common_elements = set(li1_temp) & set(li2_temp)
    print(len(common_elements))


def method4():
    common_elements = set(li1_temp).intersection(li2_temp)
    print(len(common_elements))


if __name__ == "__main__":
    li1 = []
    li2 = []
    for i in range(100000):
        li1.append(random.randint(0, 10000))
        li2.append(random.randint(0, 10000))

    li1_temp = list(set(li1))
    li2_temp = list(set(li2))

    methods = [method1, method2, method3, method4]
    for m in methods:
        start = time.perf_counter()
        m()
        end = time.perf_counter()
        print(Decimal((end - start)))

If you run this code you can see that if you use list or generator(if you iterate over generator, not just use it. I did this when I forced generator to print length of it), you get nearly same performance. But if you use set you get much better performance. Also if you use intersection method you will get a little bit better performance. the result of each method in my computer is listed bellow:

  1. method1: 0.8150673999999999974619413478649221360683441
  2. method2: 0.8329545000000001531148541289439890533685684
  3. method3: 0.0016547000000000089414697868051007390022277
  4. method4: 0.0010262999999999244948867271887138485908508

TreeMap sort by value

This can't be done by using a Comparator, as it will always get the key of the map to compare. TreeMap can only sort by the key.

How do I access store state in React Redux?

You want to do more than just getState. You want to react to changes in the store.

If you aren't using react-redux, you can do this:

function rerender() {
    const state = store.getState();
    render(
        <div>
            { state.items.map((item) => <p> {item.title} </p> )}
        </div>,
        document.getElementById('app')
    );
}

// subscribe to store
store.subscribe(rerender);

// do initial render
rerender();

// dispatch more actions and view will update

But better is to use react-redux. In this case you use the Provider like you mentioned, but then use connect to connect your component to the store.

how to configure lombok in eclipse luna

I have met with the exact same problem. And it turns out that the configuration file generated by gradle asks for java1.7.
While my system has java1.8 installed.

After modifying the compiler compliance level to 1.8. All things are working as expected.

Error: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'

I just solved it. You need to install Entity Framework again in your solution. Follow any of the approaches.

First = Right Click your Solution or Project root and click Manage NuGet Packages. Select 'EntityFramework', select the appropriate Projects and click Ok.

or

Second = Go to Console Package Manager and run Install-Package EntityFramework.

Hope it helps.

Extract filename and extension in Bash

Building from Petesh answer, if only the filename is needed, both path and extension can be stripped in a single line,

filename=$(basename ${fullname%.*})

How to save a plot into a PDF file without a large margin around

It seems to me that all approaches (file exchange solutions unconsidered) here are lacking the essential step, or finally leading to it via some blurry workarounds.

The figure size needs to equal the paper size and the white margins are gone.

A = hgload('myFigure.fig');

% set desired output size
set(A, 'Units','centimeters')
height = 15;
width = 19;

% the last two parameters of 'Position' define the figure size
set(A, 'Position',[25 5 width height],...
       'PaperSize',[width height],...
       'PaperPositionMode','auto',...
       'InvertHardcopy', 'off',...
       'Renderer','painters'...     %recommended if there are no alphamaps
   );

saveas(A,'printout','pdf')

Will give you a pdf output as your figure appears, in exactly the size you want. If you want to get it even tighter you can combine this solution with the answer of b3.

How does Junit @Rule work?

Rules are used to enhance the behaviour of each test method in a generic way. Junit rule intercept the test method and allows us to do something before a test method starts execution and after a test method has been executed.

For example, Using @Timeout rule we can set the timeout for all the tests.

public class TestApp {
    @Rule
    public Timeout globalTimeout = new Timeout(20, TimeUnit.MILLISECONDS);

    ......
    ......

 }

@TemporaryFolder rule is used to create temporary folders, files. Every time the test method is executed, a temporary folder is created and it gets deleted after the execution of the method.

public class TempFolderTest {

 @Rule
 public TemporaryFolder tempFolder= new TemporaryFolder();

 @Test
 public void testTempFolder() throws IOException {
  File folder = tempFolder.newFolder("demos");
  File file = tempFolder.newFile("Hello.txt");

  assertEquals(folder.getName(), "demos");
  assertEquals(file.getName(), "Hello.txt");

 }


}

You can see examples of some in-built rules provided by junit at this link.

Converting a UNIX Timestamp to Formatted Date String

It is very important to set a default timezone to get the correct result

<?php
// set default timezone
date_default_timezone_set('Europe/Berlin');

// timestamp
$timestamp = 1307595105;

// output
echo date('d M Y H:i:s Z',$timestamp);
echo date('c',$timestamp);
?> 

Online conversion help: http://freeonlinetools24.com/timestamp

NoSql vs Relational database

NoSQL is better than RDBMS because of the following reasons/properities of NoSQL

  1. It supports semi-structured data and volatile data
  2. It does not have schema
  3. Read/Write throughput is very high
  4. Horizontal scalability can be achieved easily
  5. Will support Bigdata in volumes of Terra Bytes & Peta Bytes
  6. Provides good support for Analytic tools on top of Bigdata
  7. Can be hosted in cheaper hardware machines
  8. In-memory caching option is available to increase the performance of queries
  9. Faster development life cycles for developers

EDIT:

To answer "why RDBMS cannot scale", please take a look at RDBMS Overheads pdf written by Stavros Harizopoulos,Daniel J. Abadi,Samuel Madden and Michael Stonebraker

RDBMS's have challenges in handling huge data volumes of Terabytes & Peta bytes. Even if you have Redundant Array of Independent/Inexpensive Disks (RAID) & data shredding, it does not scale well for huge volume of data. You require very expensive hardware.

Logging: Assembling log records and tracking down all changes in database structures slows performance. Logging may not be necessary if recoverability is not a requirement or if recoverability is provided through other means (e.g., other sites on the network).

Locking: Traditional two-phase locking poses a sizeable overhead since all accesses to database structures are governed by a separate entity, the Lock Manager.

Latching: In a multi-threaded database, many data structures have to be latched before they can be accessed. Removing this feature and going to a single-threaded approach has a noticeable performance impact.

Buffer management: A main memory database system does not need to access pages through a buffer pool, eliminating a level of indirection on every record access.

This does not mean that we have to use NoSQL over SQL.

Still, RDBMS is better than NoSQL for the following reasons/properties of RDBMS

  1. Transactions with ACID properties - Atomicity, Consistency, Isolation & Durability
  2. Adherence to Strong Schema of data being written/read
  3. Real time query management ( in case of data size < 10 Tera bytes )
  4. Execution of complex queries involving join & group by clauses

We have to use RDBMS (SQL) and NoSQL (Not only SQL) depending on the business case & requirements

Random element from string array

Just store the index generated in a variable, and then access the array using this varaible:

int idx = new Random().nextInt(fruits.length);
String random = (fruits[idx]);

P.S. I usually don't like generating new Random object per randoization - I prefer using a single Random in the program - and re-use it. It allows me to easily reproduce a problematic sequence if I later find any bug in the program.

According to this approach, I will have some variable Random r somewhere, and I will just use:

int idx = r.nextInt(fruits.length)

However, your approach is OK as well, but you might have hard time reproducing a specific sequence if you need to later on.

Disabling vertical scrolling in UIScrollView

Include the following method

-(void)viewDidLayoutSubviews{
    self.automaticallyAdjustsScrollViewInsets = NO;
}

and set the content size width of the scroll view equal to the width of the scroll view.

Can we have multiple <tbody> in same <table>?

I have created a JSFiddle where I have two nested ng-repeats with tables, and the parent ng-repeat on tbody. If you inspect any row in the table, you will see there are six tbody elements, i.e. the parent level.

HTML

<div>
        <table class="table table-hover table-condensed table-striped">
            <thead>
                <tr>
                    <th>Store ID</th>
                    <th>Name</th>
                    <th>Address</th>
                    <th>City</th>
                    <th>Cost</th>
                    <th>Sales</th>
                    <th>Revenue</th>
                    <th>Employees</th>
                    <th>Employees H-sum</th>
                </tr>
            </thead>
            <tbody data-ng-repeat="storedata in storeDataModel.storedata">
                <tr id="storedata.store.storeId" class="clickableRow" title="Click to toggle collapse/expand day summaries for this store." data-ng-click="selectTableRow($index, storedata.store.storeId)">
                    <td>{{storedata.store.storeId}}</td>
                    <td>{{storedata.store.storeName}}</td>
                    <td>{{storedata.store.storeAddress}}</td>
                    <td>{{storedata.store.storeCity}}</td>
                    <td>{{storedata.data.costTotal}}</td>
                    <td>{{storedata.data.salesTotal}}</td>
                    <td>{{storedata.data.revenueTotal}}</td>
                    <td>{{storedata.data.averageEmployees}}</td>
                    <td>{{storedata.data.averageEmployeesHours}}</td>
                </tr>
                <tr data-ng-show="dayDataCollapse[$index]">
                    <td colspan="2">&nbsp;</td>
                    <td colspan="7">
                        <div>
                            <div class="pull-right">
                                <table class="table table-hover table-condensed table-striped">
                                    <thead>
                                        <tr>
                                            <th></th>
                                            <th>Date [YYYY-MM-dd]</th>
                                            <th>Cost</th>
                                            <th>Sales</th>
                                            <th>Revenue</th>
                                            <th>Employees</th>
                                            <th>Employees H-sum</th>
                                        </tr>
                                    </thead>
                                    <tbody>
                                        <tr data-ng-repeat="dayData in storeDataModel.storedata[$index].data.dayData">
                                            <td class="pullright">
                                                <button type="btn btn-small" title="Click to show transactions for this specific day..." data-ng-click=""><i class="icon-list"></i>
                                                </button>
                                            </td>
                                            <td>{{dayData.date}}</td>
                                            <td>{{dayData.cost}}</td>
                                            <td>{{dayData.sales}}</td>
                                            <td>{{dayData.revenue}}</td>
                                            <td>{{dayData.employees}}</td>
                                            <td>{{dayData.employeesHoursSum}}</td>
                                        </tr>
                                    </tbody>
                                </table>
                            </div>
                        </div>
                    </td>
                </tr>
            </tbody>
        </table>
    </div>

( Side note: This fills up the DOM if you have a lot of data on both levels, so I am therefore working on a directive to fetch data and replace, i.e. adding into DOM when clicking parent and removing when another is clicked or same parent again. To get the kind of behavior you find on Prisjakt.nu, if you scroll down to the computers listed and click on the row (not the links). If you do that and inspect elements you will see that a tr is added and then removed if parent is clicked again or another. )

Python interpreter error, x takes no arguments (1 given)

Make sure, that all of your class methods (updateVelocity, updatePosition, ...) take at least one positional argument, which is canonically named self and refers to the current instance of the class.

When you call particle.updateVelocity(), the called method implicitly gets an argument: the instance, here particle as first parameter.

How can I check for IsPostBack in JavaScript?

hi try the following ...

function pageLoad (sender, args) {

alert (args._isPartialLoad);

}

the result is a Boolean

What is secret key for JWT based authentication and how to generate it?

What is the secret key

The secret key is combined with the header and the payload to create a unique hash. You are only able to verify this hash if you have the secret key.

How to generate the key

You can choose a good, long password. Or you can generate it from a site like this.

Example (but don't use this one now):

8Zz5tw0Ionm3XPZZfN0NOml3z9FMfmpgXwovR9fp6ryDIoGRM8EPHAB6iHsc0fb

How do I find the mime-type of a file with php?

According to the php manual, the finfo-file function is best way to do this. However, you will need to install the FileInfo PECL extension.

If the extension is not an option, you can use the outdated mime_content_type function.

What does @media screen and (max-width: 1024px) mean in CSS?

It targets some specified feature to execute some other codes...

For example:

@media all and (max-width: 600px) {
  .navigation {
    -webkit-flex-flow: column wrap;
    flex-flow: column wrap;
    padding: 0;

  }

the above snippet say if the device that run this program have screen with 600px or less than 600px width, in this case our program must execute this part .

How to get the index of a maximum element in a NumPy array along one axis

>>> import numpy as np
>>> a = np.array([[1,2,3],[4,3,1]])
>>> i,j = np.unravel_index(a.argmax(), a.shape)
>>> a[i,j]
4

What is the difference between cache and persist?

Spark gives 5 types of Storage level

  • MEMORY_ONLY
  • MEMORY_ONLY_SER
  • MEMORY_AND_DISK
  • MEMORY_AND_DISK_SER
  • DISK_ONLY

cache() will use MEMORY_ONLY. If you want to use something else, use persist(StorageLevel.<*type*>).

By default persist() will store the data in the JVM heap as unserialized objects.

Modifying list while iterating

Never alter the container you're looping on, because iterators on that container are not going to be informed of your alterations and, as you've noticed, that's quite likely to produce a very different loop and/or an incorrect one. In normal cases, looping on a copy of the container helps, but in your case it's clear that you don't want that, as the container will be empty after 50 legs of the loop and if you then try popping again you'll get an exception.

What's anything BUT clear is, what behavior are you trying to achieve, if any?! Maybe you can express your desires with a while...?

i = 0
while i < len(some_list):
    print i,                         
    print some_list.pop(0),                  
    print some_list.pop(0)

What is the best way to exit a function (which has no return value) in python before the function ends (e.g. a check fails)?

I would suggest:

def foo(element):
    do something
    if not check: return
    do more (because check was succesful)
    do much much more...

Path.Combine absolute with relative path strings

Call Path.GetFullPath on the combined path http://msdn.microsoft.com/en-us/library/system.io.path.getfullpath.aspx

> Path.GetFullPath(Path.Combine(@"C:\blah\",@"..\bling"))
C:\bling

(I agree Path.Combine ought to do this by itself)

Execution failed app:processDebugResources Android Studio

Banged my head around this for 2 days.

TL;DR - Got this error since My app name contained '-'.

Turn out android does not allowed that. After running gradlew build --stacktrace inside android directory - got an error that implies that.

Best way to store time (hh:mm) in a database

DATETIME start DATETIME end

I implore you to use two DATETIME values instead, labelled something like event_start and event_end.

Time is a complex business

Most of the world has now adopted the denery based metric system for most measurements, rightly or wrongly. This is good overall, because at least we can all agree that a g, is a ml, is a cubic cm. At least approximately so. The metric system has many flaws, but at least it's internationally consistently flawed.

With time however, we have; 1000 milliseconds in a second, 60 seconds to a minute, 60 minutes to an hour, 12 hours for each half a day, approximately 30 days per month which vary by the month and even year in question, each country has its time offset from others, the way time is formatted in each country vary.

It's a lot to digest, but the long and short of it is impossible for such a complex scenario to have a simple solution.

Some corners can be cut, but there are those where it is wiser not to

Although the top answer here suggests that you store an integer of minutes past midnight might seem perfectly reasonable, I have learned to avoid doing so the hard way.

The reasons to implement two DATETIME values are for an increase in accuracy, resolution and feedback.

These are all very handy for when the design produces undesirable results.

Am I storing more data than required?

It might initially appear like more information is being stored than I require, but there is a good reason to take this hit.

Storing this extra information almost always ends up saving me time and effort in the long-run, because I inevitably find that when somebody is told how long something took, they'll additionally want to know when and where the event took place too.

It's a huge planet

In the past, I have been guilty of ignoring that there are other countries on this planet aside from my own. It seemed like a good idea at the time, but this has ALWAYS resulted in problems, headaches and wasted time later on down the line. ALWAYS consider all time zones.

C#

A DateTime renders nicely to a string in C#. The ToString(string Format) method is compact and easy to read.

E.g.

new TimeSpan(EventStart.Ticks - EventEnd.Ticks).ToString("h'h 'm'm 's's'")

SQL server

Also if you're reading your database seperate to your application interface, then dateTimes are pleasnat to read at a glance and performing calculations on them are straightforward.

E.g.

SELECT DATEDIFF(MINUTE, event_start, event_end)

ISO8601 date standard

If using SQLite then you don't have this, so instead use a Text field and store it in ISO8601 format eg.

"2013-01-27T12:30:00+0000"

Notes:

  • This uses 24 hour clock*

  • The time offset (or +0000) part of the ISO8601 maps directly to longitude value of a GPS coordiate (not taking into account daylight saving or countrywide).

E.g.

TimeOffset=(±Longitude.24)/360 

...where ± refers to east or west direction.

It is therefore worth considering if it would be worth storing longitude, latitude and altitude along with the data. This will vary in application.

  • ISO8601 is an international format.

  • The wiki is very good for further details at http://en.wikipedia.org/wiki/ISO_8601.

  • The date and time is stored in international time and the offset is recorded depending on where in the world the time was stored.

In my experience there is always a need to store the full date and time, regardless of whether I think there is when I begin the project. ISO8601 is a very good, futureproof way of doing it.

Additional advice for free

It is also worth grouping events together like a chain. E.g. if recording a race, the whole event could be grouped by racer, race_circuit, circuit_checkpoints and circuit_laps.

In my experience, it is also wise to identify who stored the record. Either as a seperate table populated via trigger or as an additional column within the original table.

The more you put in, the more you get out

I completely understand the desire to be as economical with space as possible, but I would rarely do so at the expense of losing information.

A rule of thumb with databases is as the title says, a database can only tell you as much as it has data for, and it can be very costly to go back through historical data, filling in gaps.

The solution is to get it correct first time. This is certainly easier said than done, but you should now have a deeper insight of effective database design and subsequently stand a much improved chance of getting it right the first time.

The better your initial design, the less costly the repairs will be later on.

I only say all this, because if I could go back in time then it is what I'd tell myself when I got there.

How to check if an array is empty?

you may use yourArray.length to findout number of elements in an array.

Make sure yourArray is not null before doing yourArray.length, otherwise you will end up with NullPointerException.

Neither BindingResult nor plain target object for bean name available as request attr

I worked on this same issue and I am sure I have found out the exact reason for it.

Neither BindingResult nor plain target object for bean name 'command' available as request attribute

If your successView property value (name of jsp page) is the same as your input page name, then second value of ModelAndView constructor must be match with the commandName of the input page.

E.g.

index.jsp

<html>
<body>
    <table>
        <tr><td><a href="Login.html">Login</a></td></tr>
    </table>
</body>
</html>

dispatcher-servlet.xml

<bean id="viewResolver"
    class="org.springframework.web.servlet.view.InternalResourceViewResolver">

    <property name="prefix">
        <value>/WEB-INF/jsp/</value>
    </property>
    <property name="suffix">
        <value>.jsp</value>
    </property>
</bean>
<bean id="urlMapping"
    class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="urlMap">
        <map>              
            <entry key="/Login.html">
                <ref bean="userController"/>
            </entry>
        </map>          
    </property>             
</bean>     
 <bean id="userController" class="controller.AddCountryFormController">     
       <property name="commandName"><value>country</value></property>
       <property name="commandClass"><value>controller.Country</value></property>        
       <property name="formView"><value>countryForm</value></property>
       <property name="successView"><value>countryForm</value></property>
   </bean>      

AddCountryFormController.java

package controller;

import javax.servlet.http.*;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.validation.BindException;
import org.springframework.web.servlet.mvc.SimpleFormController;


public class AddCountryFormController extends SimpleFormController
{

    public AddCountryFormController(){
        setCommandName("Country.class");
    }

    protected ModelAndView onSubmit(HttpServletRequest request,HttpServletResponse response,Object command,BindException errors){

            Country country=(Country)command;

            System.out.println("calling onsubmit method !!!!!");

        return new ModelAndView(getSuccessView(),"country",country);

    }

}

Country.java

package controller;

public class Country
{
    private String countryName;

    public void setCountryName(String value){
        countryName=value;
    }

    public String getCountryName(){
        return countryName;
    }

}

countryForm.jsp

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<html>
<body>
    <form:form commandName="country" method="POST" >
            <table>
                    <tr><td><form:input path="countryName"/></td></tr>
                    <tr><td><input type="submit" value="Save"/></td></tr>
            </table>
    </form:form>
</body>
<html>

Input page commandName="country" ModelAndView Constructor as return new ModelAndView(getSuccessView(),"country",country); Means inputpage commandName==ModeAndView(,"commandName",)

Stop setInterval

we can easily stop the set interval by calling clear interval

var count = 0 , i = 5;
var vary = function intervalFunc() {
  count++;
      console.log(count);
    console.log('hello boy');  
    if (count == 10) {
      clearInterval(this);
    }
}

  setInterval(vary, 1500);

basic authorization command for curl

Use the -H header again before the Authorization:Basic things. So it will be

curl -i \
    -H 'Accept:application/json' \
    -H 'Authorization:Basic BASE64_string' \
    http://example.com

Here, BASE64_string = Base64 of username:password

EXC_BAD_ACCESS signal received

When you have infinite recursion, I think you can also have this error. This was a case for me.

Why do I get "Exception; must be caught or declared to be thrown" when I try to compile my Java code?

In your 'encrypt' method, you should either get rid of the try/catch and instead add a try/catch around where you call encrypt (inside 'actionPerformed') or return null inside the catch within encrypt (that's the second error.

How to filter Android logcat by application?

I have found an app on the store which can show the name / process of a log. Since Android Studio just puts a (?) on the logs being generated by the other processes, I found it useful to know which process is generating this log. But still this app is missing the filter by the process name. You can find it here.

Ordering issue with date values when creating pivot tables

April 20, 2017

I've read all the previously posted answers, and they require a lot of extra work. The quick and simple solution I have found is as follows:

1) Un-group the date field in the pivot table. 2) Go to the Pivot Field List UI. 3) Re-arrange your fields so that the Date field is listed FIRST in the ROWS section. 4) Under the Design menu, select Report Layout / Show in Tabular Form.

By default, Excel sorts by the first field in a pivot table. You may not want the Date field to be first, but it's a compromise that will save you time and much work.

Virtualhost For Wildcard Subdomain and Static Subdomain

<VirtualHost *:80>
  DocumentRoot /var/www/app1
  ServerName app1.example.com
</VirtualHost>

<VirtualHost *:80>
  DocumentRoot /var/www/example
  ServerName example.com
</VirtualHost>

<VirtualHost *:80>
  DocumentRoot /var/www/wildcard
  ServerName other.example.com
  ServerAlias *.example.com
</VirtualHost>

Should work. The first entry will become the default if you don't get an explicit match. So if you had app.otherexample.com point to it, it would be caught be app1.example.com.

Switch focus between editor and integrated terminal in Visual Studio Code

Here is a way to add your own keybinding for switching focus.

  1. Open your VSCode
  2. Press Ctrl+Shift+P and search for keyboard shortcuts and hit this (Preferences: Open Keyboard shortcuts).
  3. Search for 'focus terminal' in the search panel and find this option (Terminal: Focus on Terminal View) and click on the plus icon.

enter image description here

  1. Enter the shortcut as you like which is not used and hit Enter.
  2. Go to Editor mode and try using your shortcut.
  3. Now hit Alt+Shift+T to go to the terminal.
  4. Want to go back to the editor? Just Hit Ctrl+tab

Tested on Windows 10 machine with VSCode(1.52.1)

How to set javascript variables using MVC4 with Razor

I've seen several approaches to working around the bug, and I ran some timing tests to see what works for speed (http://jsfiddle.net/5dwwy/)

Approaches:

  1. Direct assignment

    In this approach, the razor syntax is directly assigned to the variable. This is what throws the error. As a baseline, the JavaScript speed test simply does a straight assignment of a number to a variable.

  2. Pass through `Number` constructor

    In this approach, we wrap the razor syntax in a call to the `Number` constructor, as in `Number(@ViewBag.Value)`.

  3. ParseInt

    In this approach, the razor syntax is put inside quotes and passed to the `parseInt` function.

  4. Value-returning function

    In this approach, a function is created that simply takes the razor syntax as a parameter and returns it.

  5. Type-checking function

    In this approach, the function performs some basic type checking (looking for null, basically) and returns the value if it isn't null.

Procedure:

Using each approach mentioned above, a for-loop repeats each function call 10M times, getting the total time for the entire loop. Then, that for-loop is repeated 30 times to obtain an average time per 10M actions. These times were then compared to each other to determine which actions were faster than others.

Note that since it is JavaScript running, the actual numbers other people receive will differ, but the importance is not in the actual number, but how the numbers compare to the other numbers.

Results:

Using the Direct assignment approach, the average time to process 10M assignments was 98.033ms. Using the Number constructor yielded 1554.93ms per 10M. Similarly, the parseInt method took 1404.27ms. The two function calls took 97.5ms for the simple function and 101.4ms for the more complex function.

Conclusions:

The cleanest code to understand is the Direct assignment. However, because of the bug in Visual Studio, this reports an error and could cause issues with Intellisense and give a vague sense of being wrong.

The fastest code was the simple function call, but only by a slim margin. Since I didn't do further analysis, I do not know if this difference has a statistical significance. The type-checking function was also very fast, only slightly slower than a direct assignment, and includes the possibility that the variable may be null. It's not really practical, though, because even the basic function will return undefined if the parameter is undefined (null in razor syntax).

Parsing the razor value as an int and running it through the constructor were extremely slow, on the order of 15x slower than a direct assignment. Most likely the Number constructor is actually internally calling parseInt, which would explain why it takes longer than a simple parseInt. However, they do have the advantage of being more meaningful, without requiring an externally-defined (ie somewhere else in the file or application) function to execute, with the Number constructor actually minimizing the visible casting of an integer to a string.

Bottom line, these numbers were generated running through 10M iterations. On a single item, the speed is incalculably small. For most, simply running it through the Number constructor might be the most readable code, despite being the slowest.

Sockets: Discover port availability using Java

In my case I had to use DatagramSocket class.

boolean isPortOccupied(int port) {
    DatagramSocket sock = null;
    try {
        sock = new DatagramSocket(port);
        sock.close();
        return false;
    } catch (BindException ignored) {
        return true;
    } catch (SocketException ex) {
        System.out.println(ex);
        return true;
    }
}

Don't forget to import first

import java.net.DatagramSocket;
import java.net.BindException;
import java.net.SocketException;

ASP.NET Core - Swashbuckle not creating swagger.json file

I was able to fix and understand my issue when I tried to go to the swagger.json URL location:

https://localhost:XXXXX/swagger/v1/swagger.json

The page will show the error and reason why it is not found.

In my case, I saw that there was a misconfigured XML definition of one of my methods based on the error it returned:

NotSupportedException: HTTP method "GET" & path "api/Values/{id}" overloaded by actions - ...
...
...

Delete all rows in a table based on another table

I think that you might get a little more performance if you tried this

DELETE FROM Table1
WHERE EXISTS (
  SELECT 1
  FROM Table2
  WHERE Table1.ID = Table2.ID
)

String replace method is not replacing characters

You should re-assign the result of the replacement, like this:

 sentence = sentence.replace("and", " ");

Be aware that the String class is immutable, meaning that all of its methods return a new string and never modify the original string in-place, so the result of invoking a method in an instance of String must be assigned to a variable or used immediately for the change to take effect.

How to disassemble a memory range with GDB?

fopen() is a C library function and so you won't see any syscall instructions in your code, just a regular function call. At some point, it does call open(2), but it does that via a trampoline. There is simply a jump to the VDSO page, which is provided by the kernel to every process. The VDSO then provides code to make the system call. On modern processors, the SYSCALL or SYSENTER instructions will be used, but you can also use INT 80h on x86 processors.

How do I center align horizontal <UL> menu?

div {
     text-align: center;
}
div ul {
     display: inline-table;
}

ul as inline-table fixes the with issue. I used the parent div to align the text to center. this way it looks good even in other languages (translation, different width)

Getting Excel to refresh data on sheet from within VBA

Sometimes Excel will hiccup and needs a kick-start to reapply an equation. This happens in some cases when you are using custom formulas.

Make sure that you have the following script

ActiveSheet.EnableCalculation = True

Reapply the equation of choice.

Cells(RowA,ColB).Formula = Cells(RowA,ColB).Formula

This can then be looped as needed.

Receiving login prompt using integrated windows authentication

In our Intranet the issue was solved on the client side by tweaking settings in security as shown here. Either of the check boxes on the right worked for us.

IE Internet Options

How to show an alert box in PHP?

When I just run this as a page

<?php
echo '<script language="javascript">';
echo 'alert("message successfully sent")';
echo '</script>';
exit;

it works fine.

What version of PHP are you running?

Could you try echoing something else after: $testObject->split_for_sms($Chat);

Maybe it doesn't get to that part of the code? You could also try these with the other function calls to check where your program stops/is getting to.

Hope you get a bit further with this.

What's sizeof(size_t) on 32-bit vs the various 64-bit data models?

size_t is defined by the C standard to be the unsigned integer return type of the sizeof operator (C99 6.3.5.4.4), and the argument of malloc and friends (C99 7.20.3.3 etc). The actual range is set such that the maximum (SIZE_MAX) is at least 65535 (C99 7.18.3.2).

However, this doesn't let us determine sizeof(size_t). The implementation is free to use any representation it likes for size_t - so there is no upper bound on size - and the implementation is also free to define a byte as 16-bits, in which case size_t can be equivalent to unsigned char.

Putting that aside, however, in general you'll have 32-bit size_t on 32-bit programs, and 64-bit on 64-bit programs, regardless of the data model. Generally the data model only affects static data; for example, in GCC:

`-mcmodel=small'
     Generate code for the small code model: the program and its
     symbols must be linked in the lower 2 GB of the address space.
     Pointers are 64 bits.  Programs can be statically or dynamically
     linked.  This is the default code model.

`-mcmodel=kernel'
     Generate code for the kernel code model.  The kernel runs in the
     negative 2 GB of the address space.  This model has to be used for
     Linux kernel code.

`-mcmodel=medium'
     Generate code for the medium model: The program is linked in the
     lower 2 GB of the address space but symbols can be located
     anywhere in the address space.  Programs can be statically or
     dynamically linked, but building of shared libraries are not
     supported with the medium model.

`-mcmodel=large'
     Generate code for the large model: This model makes no assumptions
     about addresses and sizes of sections.

You'll note that pointers are 64-bit in all cases; and there's little point to having 64-bit pointers but not 64-bit sizes, after all.

Submit HTML form, perform javascript function (alert then redirect)

You need to prevent the default behaviour. You can either use e.preventDefault() or return false; In this case, the best thing is, you can use return false; here:

<form onsubmit="completeAndRedirect(); return false;">

wp_nav_menu change sub-menu class name?

Like it always is, after having looked for a long time before writing something to the site, just a minute after I posted here I found my solution.

It thought I'd share it here so someone else can find it.

//Add "parent" class to pages with subpages, change submenu class name, add depth class

    class Prio_Walker extends Walker_Nav_Menu {
    function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ){
        $GLOBALS['dd_children'] = ( isset($children_elements[$element->ID]) )? 1:0;
        $GLOBALS['dd_depth'] = (int) $depth;
        parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
    }

     function start_lvl(&$output, $depth) {
    $indent = str_repeat("\t", $depth);
    $output .= "\n$indent<ul class=\"children level-".$depth."\">\n";
  }
}

add_filter('nav_menu_css_class','add_parent_css',10,2);
function  add_parent_css($classes, $item){
     global  $dd_depth, $dd_children;
     $classes[] = 'depth'.$dd_depth;
     if($dd_children)
         $classes[] = 'parent';
    return $classes;
}

//Add class to parent pages to show they have subpages (only for automatic wp_nav_menu)

function add_parent_class( $css_class, $page, $depth, $args )
{
   if ( ! empty( $args['has_children'] ) )
       $css_class[] = 'parent';
   return $css_class;
}
add_filter( 'page_css_class', 'add_parent_class', 10, 4 );

This is where I found the solution: Solution in WordPress support forum

Sql Server 'Saving changes is not permitted' error ? Prevent saving changes that require table re-creation

If you use sql server Management studio go to Tools >> Options >> Designers and uncheck “Prevent Saving changes that require table re-creation” It works with me

How do I connect to a MySQL Database in Python?

Here's one way to do it, using MySQLdb, which only supports Python 2:

#!/usr/bin/python
import MySQLdb

# Connect
db = MySQLdb.connect(host="localhost",
                     user="appuser",
                     passwd="",
                     db="onco")

cursor = db.cursor()

# Execute SQL select statement
cursor.execute("SELECT * FROM location")

# Commit your changes if writing
# In this case, we are only reading data
# db.commit()

# Get the number of rows in the resultset
numrows = cursor.rowcount

# Get and display one row at a time
for x in range(0, numrows):
    row = cursor.fetchone()
    print row[0], "-->", row[1]

# Close the connection
db.close()

Reference here

Convert string date to timestamp in Python

To convert the string into a date object:

from datetime import date, datetime

date_string = "01/12/2011"
date_object = date(*map(int, reversed(date_string.split("/"))))
assert date_object == datetime.strptime(date_string, "%d/%m/%Y").date()

The way to convert the date object into POSIX timestamp depends on timezone. From Converting datetime.date to UTC timestamp in Python:

  • date object represents midnight in UTC

    import calendar
    
    timestamp1 = calendar.timegm(utc_date.timetuple())
    timestamp2 = (utc_date.toordinal() - date(1970, 1, 1).toordinal()) * 24*60*60
    assert timestamp1 == timestamp2
    
  • date object represents midnight in local time

    import time
    
    timestamp3 = time.mktime(local_date.timetuple())
    assert timestamp3 != timestamp1 or (time.gmtime() == time.localtime())
    

The timestamps are different unless midnight in UTC and in local time is the same time instance.

How to write a multiline Jinja statement

According to the documentation: https://jinja.palletsprojects.com/en/2.10.x/templates/#line-statements you may use multi-line statements as long as the code has parens/brackets around it. Example:

{% if ( (foo == 'foo' or bar == 'bar') and 
        (fooo == 'fooo' or baar == 'baar') ) %}
    <li>some text</li>
{% endif %}

Edit: Using line_statement_prefix = '#'* the code would look like this:

# if ( (foo == 'foo' or bar == 'bar') and 
       (fooo == 'fooo' or baar == 'baar') )
    <li>some text</li>
# endif

*Here's an example of how you'd specify the line_statement_prefix in the Environment:

from jinja2 import Environment, PackageLoader, select_autoescape
env = Environment(
    loader=PackageLoader('yourapplication', 'templates'),
    autoescape=select_autoescape(['html', 'xml']),
    line_statement_prefix='#'
)

Or using Flask:

from flask import Flask
app = Flask(__name__, instance_relative_config=True, static_folder='static')
app.jinja_env.filters['zip'] = zip
app.jinja_env.line_statement_prefix = '#'

Using Python 3 in virtualenv

Install prerequisites.

sudo apt-get install python3 python3-pip virtualenvwrapper

Create a Python3 based virtual environment. Optionally enable --system-site-packages flag.

mkvirtualenv -p /usr/bin/python3 <venv-name>

Set into the virtual environment.

workon <venv-name>

Install other requirements using pip package manager.

pip install -r requirements.txt
pip install <package_name>

When working on multiple python projects simultaneously it is usually recommended to install common packages like pdbpp globally and then reuse them in virtualenvs.

Using this technique saves a lot of time spent on fetching packages and installing them, apart from consuming minimal disk space and network bandwidth.

sudo -H pip3 -v install pdbpp
mkvirtualenv -p $(which python3) --system-site-packages <venv-name>

Django specific instructions

If there are a lot of system wide python packages then it is recommended to not use --system-site-packages flag especially during development since I have noticed that it slows down Django startup a lot. I presume Django environment initialisation is manually scanning and appending all site packages from the system path which might be the reason. Even python manage.py shell becomes very slow.

Having said that experiment which option works better. Might be safe to just skip --system-site-packages flag for Django projects.

What does "TypeError 'xxx' object is not callable" means?

The action occurs when you attempt to call an object which is not a function, as with (). For instance, this will produce the error:

>>> a = 5
>>> a()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not callable

Class instances can also be called if they define a method __call__

One common mistake that causes this error is trying to look up a list or dictionary element, but using parentheses instead of square brackets, i.e. (0) instead of [0]

How to open a file / browse dialog using javascript?

Create input element.

Missing from these answers is how to get a file dialog without a input element on the page.

The function to show the input file dialog.

function openFileDialog (accept, callback) {  // this function must be called from  a user
                                              // activation event (ie an onclick event)
    
    // Create an input element
    var inputElement = document.createElement("input");

    // Set its type to file
    inputElement.type = "file";

    // Set accept to the file types you want the user to select. 
    // Include both the file extension and the mime type
    inputElement.accept = accept;

    // set onchange event to call callback when user has selected file
    inputElement.addEventListener("change", callback)
    
    // dispatch a click event to open the file dialog
    inputElement.dispatchEvent(new MouseEvent("click")); 
}

NOTE the function must be part of a user activation such as a click event. Attempting to open the file dialog without user activation will fail.

NOTE input.accept is not used in Edge

Example.

Calling above function when user clicks an anchor element.

_x000D_
_x000D_
// wait for window to load
window.addEventListener("load", windowLoad);

// open a dialog function
function openFileDialog (accept, multy = false, callback) { 
    var inputElement = document.createElement("input");
    inputElement.type = "file";
    inputElement.accept = accept; // Note Edge does not support this attribute
    if (multy) {
        inputElement.multiple = multy;
    }
    if (typeof callback === "function") {
         inputElement.addEventListener("change", callback);
    }
    inputElement.dispatchEvent(new MouseEvent("click")); 
}

// onload event
function windowLoad () {
    // add user click event to userbutton
    userButton.addEventListener("click", openDialogClick);
}

// userButton click event
function openDialogClick () {
    // open file dialog for text files
    openFileDialog(".txt,text/plain", true, fileDialogChanged);
}

// file dialog onchange event handler
function fileDialogChanged (event) {
    [...this.files].forEach(file => {
        var div = document.createElement("div");
        div.className = "fileList common";
        div.textContent = file.name;
        userSelectedFiles.appendChild(div);
    });
}
_x000D_
.common {
    font-family: sans-serif;
    padding: 2px;
    margin : 2px;
    border-radius: 4px;
 }
.fileList {
    background: #229;
    color: white;
}
#userButton {
    background: #999;
    color: #000;
    width: 8em;
    text-align: center;
    cursor: pointer;
}

#userButton:hover {
   background : #4A4;
   color : white;
}
_x000D_
<a id = "userButton" class = "common" title = "Click to open file selection dialog">Open file dialog</a>
<div id = "userSelectedFiles" class = "common"></div>
_x000D_
_x000D_
_x000D_

Warning the above snippet is written in ES6.

How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly?

[Updated to adapt to modern pandas, which has isnull as a method of DataFrames..]

You can use isnull and any to build a boolean Series and use that to index into your frame:

>>> df = pd.DataFrame([range(3), [0, np.NaN, 0], [0, 0, np.NaN], range(3), range(3)])
>>> df.isnull()
       0      1      2
0  False  False  False
1  False   True  False
2  False  False   True
3  False  False  False
4  False  False  False
>>> df.isnull().any(axis=1)
0    False
1     True
2     True
3    False
4    False
dtype: bool
>>> df[df.isnull().any(axis=1)]
   0   1   2
1  0 NaN   0
2  0   0 NaN

[For older pandas:]

You could use the function isnull instead of the method:

In [56]: df = pd.DataFrame([range(3), [0, np.NaN, 0], [0, 0, np.NaN], range(3), range(3)])

In [57]: df
Out[57]: 
   0   1   2
0  0   1   2
1  0 NaN   0
2  0   0 NaN
3  0   1   2
4  0   1   2

In [58]: pd.isnull(df)
Out[58]: 
       0      1      2
0  False  False  False
1  False   True  False
2  False  False   True
3  False  False  False
4  False  False  False

In [59]: pd.isnull(df).any(axis=1)
Out[59]: 
0    False
1     True
2     True
3    False
4    False

leading to the rather compact:

In [60]: df[pd.isnull(df).any(axis=1)]
Out[60]: 
   0   1   2
1  0 NaN   0
2  0   0 NaN

jQuery SVG vs. Raphael

I'm a huge fan of Raphael and the development momentum seems to be going strong (version 0.85 was released late last week). Another big plus is that its developer, Dmitry Baranovskiy, is currently working on a Raphael charting plugin, g.raphael, which looks like its shaping up to be pretty slick (there are a few samples of the output from the early versions on Flickr).

However, just to throw another possible contender into the SVG library mix, Google's SVG Web looks very promising indeed (even though I'm not a big fan of Flash, which it uses to render in non-SVG compliant browsers). Probably one to watch, especially with the upcoming SVG Open conference.

Tools to generate database tables diagram with Postgresql?

PostgreSQL Autodoc has worked well for me. It is a simple command line tool. From the web page:

This is a utility which will run through PostgreSQL system tables and returns HTML, Dot, Dia and DocBook XML which describes the database.

Missing Push Notification Entitlement

The biggest problem that i have after enabling the Push Notification from Capabilities and remaking all the certificates is that the Target name and the folder name where was stored the project was composed from 2 strings separated by space. After removing the space all worked just fine!

Stopping a windows service when the stop option is grayed out

Open command prompt with admin access and type the following commands there .

a)

tasklist

it displays list of all available services . There you can see the service you want to stop/start/restart . Remember PID value of the service you want to force stop.

b) Now type

taskkill /f /PID [PID value of the service] 

and press enter. On success you will get the message “SUCCESS: The process with PID has been terminated”.

Ex : taskkill /f /PID 5088

This will forcibly kill the frozen service. You can now return to Server Manager and restart the service.

How do I join two SQLite tables in my Android application?

"Ambiguous column" usually means that the same column name appears in at least two tables; the database engine can't tell which one you want. Use full table names or table aliases to remove the ambiguity.

Here's an example I happened to have in my editor. It's from someone else's problem, but should make sense anyway.

select P.* 
from product_has_image P
inner join highest_priority_images H 
        on (H.id_product = P.id_product and H.priority = p.priority)

How can I include all JavaScript files in a directory via JavaScript file?

Another option that is pretty short:

<script type="text/javascript">
$.ajax({
  url: "/js/partials",
  success: function(data){
     $(data).find('a:contains(.js)').each(function(){
        // will loop through 
        var partial= $(this).attr("href");
        $.getScript( "/js/partials/" + partial, function( data, textStatus, jqxhr ) {});
     });
  }
});
</script>

Rotate and translate

There is no need for that, as you can use css 'writing-mode' with values 'vertical-lr' or 'vertical-rl' as desired.

.item {
  writing-mode: vertical-rl;
}

CSS:writing-mode

Adding two Java 8 streams, or an extra element to a stream

Unfortunately this answer is probably of little or no help whatsoever, but I did a forensics analysis of the Java Lambda Mailing list to see if I could find the cause of this design. This is what I found out.

In the beginning there was an instance method for Stream.concat(Stream)

In the mailing list I can clearly see the method was originally implemented as an instance method, as you can read in this thread by Paul Sandoz, about the concat operation.

In it they discuss the issues that could arise from those cases in which the stream could be infinite and what concatenation would mean in those cases, but I do not think that was the reason for the modification.

You see in this other thread that some early users of the JDK 8 questioned about the behavior of the concat instance method when used with null arguments.

This other thread reveals, though, that the design of the concat method was under discussion.

Refactored to Streams.concat(Stream,Stream)

But without any explanation, suddenly, the methods were changed to static methods, as you can see in this thread about combining streams. This is perhaps the only mail thread that sheds a bit of light about this change, but it was not clear enough for me to determine the reason for the refactoring. But we can see they did a commit in which they suggested to move the concat method out of Stream and into the helper class Streams.

Refactored to Stream.concat(Stream,Stream)

Later, it was moved again from Streams to Stream, but yet again, no explanation for that.

So, bottom line, the reason for the design is not entirely clear for me and I could not find a good explanation. I guess you could still ask the question in the mailing list.

Some Alternatives for Stream Concatenation

This other thread by Michael Hixson discusses/asks about other ways to combine/concat streams

  1. To combine two streams, I should do this:

    Stream.concat(s1, s2)
    

    not this:

    Stream.of(s1, s2).flatMap(x -> x)
    

    ... right?

  2. To combine more than two streams, I should do this:

    Stream.of(s1, s2, s3, ...).flatMap(x -> x)
    

    not this:

    Stream.of(s1, s2, s3, ...).reduce(Stream.empty(), Stream::concat)
    

    ... right?

Where does Internet Explorer store saved passwords?

I found the answer. IE stores passwords in two different locations based on the password type:

  • Http-Auth: %APPDATA%\Microsoft\Credentials, in encrypted files
  • Form-based: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\IntelliForms\Storage2, encrypted with the url

From a very good page on NirSoft.com:

Starting from version 7.0 of Internet Explorer, Microsoft completely changed the way that passwords are saved. In previous versions (4.0 - 6.0), all passwords were saved in a special location in the Registry known as the "Protected Storage". In version 7.0 of Internet Explorer, passwords are saved in different locations, depending on the type of password. Each type of passwords has some limitations in password recovery:

  • AutoComplete Passwords: These passwords are saved in the following location in the Registry: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\IntelliForms\Storage2 The passwords are encrypted with the URL of the Web sites that asked for the passwords, and thus they can only be recovered if the URLs are stored in the history file. If you clear the history file, IE PassView won't be able to recover the passwords until you visit again the Web sites that asked for the passwords. Alternatively, you can add a list of URLs of Web sites that requires user name/password into the Web sites file (see below).

  • HTTP Authentication Passwords: These passwords are stored in the Credentials file under Documents and Settings\Application Data\Microsoft\Credentials, together with login passwords of LAN computers and other passwords. Due to security limitations, IE PassView can recover these passwords only if you have administrator rights.

In my particular case it answers the question of where; and I decided that I don't want to duplicate that. I'll continue to use CredRead/CredWrite, where the user can manage their passwords from within an established UI system in Windows.

Show/Hide Multiple Divs with Jquery

_x000D_
_x000D_
jQuery(function() {_x000D_
  jQuery('#showall').click(function() {_x000D_
    jQuery('.targetDiv').show();_x000D_
  });_x000D_
  jQuery('.showSingle').click(function() {_x000D_
    jQuery('.targetDiv').hide();_x000D_
    jQuery('#div' + $(this).attr('target')).show();_x000D_
  });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
<div class="buttons">_x000D_
  <a id="showall">All</a>_x000D_
  <a class="showSingle" target="1">Div 1</a>_x000D_
  <a class="showSingle" target="2">Div 2</a>_x000D_
  <a class="showSingle" target="3">Div 3</a>_x000D_
  <a class="showSingle" target="4">Div 4</a>_x000D_
</div>_x000D_
_x000D_
<div id="div1" class="targetDiv">Lorum Ipsum1</div>_x000D_
<div id="div2" class="targetDiv">Lorum Ipsum2</div>_x000D_
<div id="div3" class="targetDiv">Lorum Ipsum3</div>_x000D_
<div id="div4" class="targetDiv">Lorum Ipsum4</div>
_x000D_
_x000D_
_x000D_

http://jsfiddle.net/XwN2L/

How to create a .gitignore file

1. Open git terminal
2. go to git repository of the project
3. create a .gitignore file by **touch .gitignore** command
4. **git add .gitignore** command to add ignore file
5. set ignore rules in the ignore file
6. run the command **cat .gitignore**

By running the command in step 3 you will get the .gitignore file in the project directory. Thanks.

Codeigniter: does $this->db->last_query(); execute a query?

For me save_queries option was turned off so,

$this->db->save_queries = TRUE; //Turn ON save_queries for temporary use.
$str = $this->db->last_query();
echo $str;

Ref: Can't get result from $this->db->last_query(); codeigniter

Build query string for System.Net.HttpClient get

TL;DR: do not use accepted version as It's completely broken in relation to handling unicode characters, and never use internal API

I've actually found weird double encoding issue with the accepted solution:

So, If you're dealing with characters which need to be encoded, accepted solution leads to double encoding:

  • query parameters are auto encoded by using NameValueCollection indexer (and this uses UrlEncodeUnicode, not regular expected UrlEncode(!))
  • Then, when you call uriBuilder.Uri it creates new Uri using constructor which does encoding one more time (normal url encoding)
  • That cannot be avoided by doing uriBuilder.ToString() (even though this returns correct Uri which IMO is at least inconsistency, maybe a bug, but that's another question) and then using HttpClient method accepting string - client still creates Uri out of your passed string like this: new Uri(uri, UriKind.RelativeOrAbsolute)

Small, but full repro:

var builder = new UriBuilder
{
    Scheme = Uri.UriSchemeHttps,
    Port = -1,
    Host = "127.0.0.1",
    Path = "app"
};

NameValueCollection query = HttpUtility.ParseQueryString(builder.Query);

query["cyrillic"] = "????????";

builder.Query = query.ToString();
Console.WriteLine(builder.Query); //query with cyrillic stuff UrlEncodedUnicode, and that's not what you want

var uri = builder.Uri; // creates new Uri using constructor which does encode and messes cyrillic parameter even more
Console.WriteLine(uri);

// this is still wrong:
var stringUri = builder.ToString(); // returns more 'correct' (still `UrlEncodedUnicode`, but at least once, not twice)
new HttpClient().GetStringAsync(stringUri); // this creates Uri object out of 'stringUri' so we still end up sending double encoded cyrillic text to server. Ouch!

Output:

?cyrillic=%u043a%u0438%u0440%u0438%u043b%u0438%u0446%u044f

https://127.0.0.1/app?cyrillic=%25u043a%25u0438%25u0440%25u0438%25u043b%25u0438%25u0446%25u044f

As you may see, no matter if you do uribuilder.ToString() + httpClient.GetStringAsync(string) or uriBuilder.Uri + httpClient.GetStringAsync(Uri) you end up sending double encoded parameter

Fixed example could be:

var uri = new Uri(builder.ToString(), dontEscape: true);
new HttpClient().GetStringAsync(uri);

But this uses obsolete Uri constructor

P.S on my latest .NET on Windows Server, Uri constructor with bool doc comment says "obsolete, dontEscape is always false", but actually works as expected (skips escaping)

So It looks like another bug...

And even this is plain wrong - it send UrlEncodedUnicode to server, not just UrlEncoded what server expects

Update: one more thing is, NameValueCollection actually does UrlEncodeUnicode, which is not supposed to be used anymore and is incompatible with regular url.encode/decode (see NameValueCollection to URL Query?).

So the bottom line is: never use this hack with NameValueCollection query = HttpUtility.ParseQueryString(builder.Query); as it will mess your unicode query parameters. Just build query manually and assign it to UriBuilder.Query which will do necessary encoding and then get Uri using UriBuilder.Uri.

Prime example of hurting yourself by using code which is not supposed to be used like this

How to set up file permissions for Laravel?

The solution posted by bgles is spot on for me in terms of correctly setting permissions initially (I use the second method), but it still has potential issues for Laravel.

By default, Apache will create files with 644 permissions. So that's pretty much anything in storage/. So, if you delete the contents of storage/framework/views, then access a page through Apache you will find the cached view has been created like:

-rw-r--r-- 1 www-data www-data 1005 Dec  6 09:40 969370d7664df9c5206b90cd7c2c79c2

If you run "artisan serve" and access a different page, you will get different permissions because CLI PHP behaves differently from Apache:

-rw-rw-r-- 1 user     www-data 16191 Dec  6 09:48 2a1683fac0674d6f8b0b54cbc8579f8e

In itself this is no big deal as you will not be doing any of this in production. But if Apache creates a file that subsequently needs to be written by the user, it will fail. And this can apply to cache files, cached views and logs when deploying using a logged-in user and artisan. A facile example being "artisan cache:clear" which will fail to delete any cache files that are www-data:www-data 644.

This can be partially mitigated by running artisan commands as www-data, so you'll be doing/scripting everything like:

sudo -u www-data php artisan cache:clear

Or you'll avoid the tediousness of this and add this to your .bash_aliases:

alias art='sudo -u www-data php artisan'

This is good enough and is not affecting security in any way. But on development machines, running testing and sanitation scripts makes this unwieldy, unless you want to set up aliases to use 'sudo -u www-data' to run phpunit and everything else you check your builds with that might cause files to be created.

The solution is to follow the second part of bgles advice, and add the following to /etc/apache2/envvars, and restart (not reload) Apache:

umask 002

This will force Apache to create files as 664 by default. In itself, this can present a security risk. However, on the Laravel environments mostly being discussed here (Homestead, Vagrant, Ubuntu) the web server runs as user www-data under group www-data. So if you do not arbitrarily allow users to join www-data group, there should be no additional risk. If someone manages to break out of the webserver, they have www-data access level anyway so nothing is lost (though that's not the best attitude to have relating to security admittedly). So on production it's relatively safe, and on a single-user development machine, it's just not an issue.

Ultimately as your user is in www-data group, and all directories containing these files are g+s (the file is always created under the group of the parent directory), anything created by the user or by www-data will be r/w for the other.

And that's the aim here.

edit

On investigating the above approach to setting permissions further, it still looks good enough, but a few tweaks can help:

By default, directories are 775 and files are 664 and all files have the owner and group of the user who just installed the framework. So assume we start from that point.

cd /var/www/projectroot
sudo chmod 750 ./
sudo chgrp www-data ./

First thing we do is block access to everyone else, and make the group to be www-data. Only the owner and members of www-data can access the directory.

sudo chmod 2775 bootstrap/cache
sudo chgrp -R www-data bootstrap/cache

To allow the webserver to create services.json and compiled.php, as suggested by the official Laravel installation guide. Setting the group sticky bit means these will be owned by the creator with a group of www-data.

find storage -type d -exec sudo chmod 2775 {} \;
find storage -type f -exec sudo chmod 664 {} \;
sudo chgrp -R www-data storage

We do the same thing with the storage folder to allow creation of cache, log, session and view files. We use find to explicitly set the directory permissions differently for directories and files. We didn't need to do this in bootstrap/cache as there aren't (normally) any sub-directories in there.

You may need to reapply any executable flags, and delete vendor/* and reinstall composer dependencies to recreate links for phpunit et al, eg:

chmod +x .git/hooks/*
rm vendor/*
composer install -o

That's it. Except for the umask for Apache explained above, this is all that's required without making the whole projectroot writeable by www-data, which is what happens with other solutions. So it's marginally safer this way in that an intruder running as www-data has more limited write access.

end edit

Changes for Systemd

This applies to the use of php-fpm, but maybe others too.

The standard systemd service needs to be overridden, the umask set in the override.conf file, and the service restarted:

sudo systemctl edit php7.0-fpm.service
Use:
    [Service]
    UMask=0002
Then:
sudo systemctl daemon-reload
sudo systemctl restart php7.0-fpm.service

How do I turn off the output from tar commands on Unix?

Just drop the option v.

-v is for verbose. If you don't use it then it won't display:

tar -zxf tmp.tar.gz -C ~/tmp1

How can I sort generic list DESC and ASC?

I was checking all the answer above and wanted to add one more additional information. I wanted to sort the list in DESC order and I was searching for the solution which is faster for bigger inputs and I was using this method earlier :-

li.Sort();
li.Reverse();

but my test cases were failing for exceeding time limits, so below solution worked for me:-

li.Sort((a, b) => b.CompareTo(a));

So Ultimately the conclusion is that 2nd way of Sorting list in Descending order is bit faster than the previous one.

What is your most productive shortcut with Vim?

The series of vim commands ggVGg? applies a Rot13 cipher to the text in your current document.

Gung vf zl zbfg cebqhpgvir fubegphg fvapr V nyjnlf glcr va Ebg13.

blur() vs. onblur()

I guess it's just because the onblur event is called as a result of the input losing focus, there isn't a blur action associated with an input, like there is a click action associated with a button

Bootstrap 3 Align Text To Bottom of Div

I think your best bet would be to use a combination of absolute and relative positioning.

Here's a fiddle: http://jsfiddle.net/PKVza/2/

given your html:

<div class="row">
    <div class="col-sm-6">
        <img src="~/Images/MyLogo.png" alt="Logo" />
    </div>
    <div class="bottom-align-text col-sm-6">
        <h3>Some Text</h3>
    </div>
</div>

use the following CSS:

@media (min-width: 768px ) {
  .row {
      position: relative;
  }

  .bottom-align-text {
    position: absolute;
    bottom: 0;
    right: 0;
  }
}

EDIT - Fixed CSS and JSFiddle for mobile responsiveness and changed the ID to a class.

SaveFileDialog setting default path and file type?

Environment.GetSystemVariable("%SystemDrive%"); will provide the drive OS installed, and you can set filters to savedialog Obtain file path of C# save dialog box

Sleep for milliseconds

The question is old, but I managed to figure out a simple way to have this in my app. You can create a C/C++ macro as shown below use it:

#ifndef MACROS_H
#define MACROS_H

#include <unistd.h>

#define msleep(X) usleep(X * 1000)

#endif // MACROS_H

ORA-12154: TNS:could not resolve the connect identifier specified (PLSQL Developer)

JUST copy and paste tnsnames and sqlnet files from Oracle home in PLSQL Developer Main folder. Use below Query to get oracle home

select substr(file_spec, 1, instr(file_spec, '\', -1, 2) -1) ORACLE_HOME from dba_libraries where library_name = 'DBMS_SUMADV_LIB';

Exception: Serialization of 'Closure' is not allowed

Direct Closure serialisation is not allowed by PHP. But you can use powefull class like PHP Super Closure : https://github.com/jeremeamia/super_closure

This class is really simple to use and is bundled into the laravel framework for the queue manager.

From the github documentation :

$helloWorld = new SerializableClosure(function ($name = 'World') use ($greeting) {
    echo "{$greeting}, {$name}!\n";
});

$serialized = serialize($helloWorld);

Hive: Filtering Data between Specified Dates when Date is a String

Just like SQL, Hive supports BETWEEN operator for more concise statement:

SELECT *
  FROM your_table
  WHERE your_date_column BETWEEN '2010-09-01' AND '2013-08-31';

How to pause / sleep thread or process in Android?

You can try this one it is short

SystemClock.sleep(7000);

WARNING: Never, ever, do this on a UI thread.

Use this to sleep eg. background thread.


Full solution for your problem will be: This is available API 1

findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(final View button) {
                button.setBackgroundResource(R.drawable.avatar_dead);
                final long changeTime = 1000L;
                button.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        button.setBackgroundResource(R.drawable.avatar_small);
                    }
                }, changeTime);
            }
        });

Without creating tmp Handler. Also this solution is better than @tronman because we do not retain view by Handler. Also we don't have problem with Handler created at bad thread ;)

Documentation

public static void sleep (long ms)

Added in API level 1

Waits a given number of milliseconds (of uptimeMillis) before returning. Similar to sleep(long), but does not throw InterruptedException; interrupt() events are deferred until the next interruptible operation. Does not return until at least the specified number of milliseconds has elapsed.

Parameters

ms to sleep before returning, in milliseconds of uptime.

Code for postDelayed from View class:

/**
 * <p>Causes the Runnable to be added to the message queue, to be run
 * after the specified amount of time elapses.
 * The runnable will be run on the user interface thread.</p>
 *
 * @param action The Runnable that will be executed.
 * @param delayMillis The delay (in milliseconds) until the Runnable
 *        will be executed.
 *
 * @return true if the Runnable was successfully placed in to the
 *         message queue.  Returns false on failure, usually because the
 *         looper processing the message queue is exiting.  Note that a
 *         result of true does not mean the Runnable will be processed --
 *         if the looper is quit before the delivery time of the message
 *         occurs then the message will be dropped.
 *
 * @see #post
 * @see #removeCallbacks
 */
public boolean postDelayed(Runnable action, long delayMillis) {
    final AttachInfo attachInfo = mAttachInfo;
    if (attachInfo != null) {
        return attachInfo.mHandler.postDelayed(action, delayMillis);
    }
    // Assume that post will succeed later
    ViewRootImpl.getRunQueue().postDelayed(action, delayMillis);
    return true;
}

How to get row from R data.frame

10 years later ---> Using tidyverse we could achieve this simply and borrowing a leaf from Christopher Bottoms. For a better grasp, see slice().

library(tidyverse)
x <- structure(list(A = c(5,    3.5, 3.25, 4.25,  1.5 ), 
                    B = c(4.25, 4,   4,    4.5,   4.5 ),
                    C = c(4.5,  2.5, 4,    2.25,  3   )
),
.Names    = c("A", "B", "C"),
class     = "data.frame",
row.names = c(NA, -5L)
)

x
#>      A    B    C
#> 1 5.00 4.25 4.50
#> 2 3.50 4.00 2.50
#> 3 3.25 4.00 4.00
#> 4 4.25 4.50 2.25
#> 5 1.50 4.50 3.00

y<-c(A=5, B=4.25, C=4.5)
y
#>    A    B    C 
#> 5.00 4.25 4.50

#The slice() verb allows one to subset data row-wise. 
x <- x %>% slice(1) #(n) for the nth row, or (i:n) for range i to n, (i:n()) for i to last row...

x
#>   A    B   C
#> 1 5 4.25 4.5

#Test that the items in the row match the vector you wanted
x[1,]==y
#>      A    B    C
#> 1 TRUE TRUE TRUE

Created on 2020-08-06 by the reprex package (v0.3.0)

Change color inside strings.xml

You do not set such attributes in strings.xml type of files. You need to set it in your code. or (which is better solution) create style with colors you want and apply to your TextView

Python: Converting from ISO-8859-1/latin1 to UTF-8

This is a common problem, so here's a relatively thorough illustration.

For non-unicode strings (i.e. those without u prefix like u'\xc4pple'), one must decode from the native encoding (iso8859-1/latin1, unless modified with the enigmatic sys.setdefaultencoding function) to unicode, then encode to a character set that can display the characters you wish, in this case I'd recommend UTF-8.

First, here is a handy utility function that'll help illuminate the patterns of Python 2.7 string and unicode:

>>> def tell_me_about(s): return (type(s), s)

A plain string

>>> v = "\xC4pple" # iso-8859-1 aka latin1 encoded string

>>> tell_me_about(v)
(<type 'str'>, '\xc4pple')

>>> v
'\xc4pple'        # representation in memory

>>> print v
?pple             # map the iso-8859-1 in-memory to iso-8859-1 chars
                  # note that '\xc4' has no representation in iso-8859-1, 
                  # so is printed as "?".

Decoding a iso8859-1 string - convert plain string to unicode

>>> uv = v.decode("iso-8859-1")
>>> uv
u'\xc4pple'       # decoding iso-8859-1 becomes unicode, in memory

>>> tell_me_about(uv)
(<type 'unicode'>, u'\xc4pple')

>>> print v.decode("iso-8859-1")
Äpple             # convert unicode to the default character set
                  # (utf-8, based on sys.stdout.encoding)

>>> v.decode('iso-8859-1') == u'\xc4pple'
True              # one could have just used a unicode representation 
                  # from the start

A little more illustration — with “Ä”

>>> u"Ä" == u"\xc4"
True              # the native unicode char and escaped versions are the same

>>> "Ä" == u"\xc4"  
False             # the native unicode char is '\xc3\x84' in latin1

>>> "Ä".decode('utf8') == u"\xc4"
True              # one can decode the string to get unicode

>>> "Ä" == "\xc4"
False             # the native character and the escaped string are
                  # of course not equal ('\xc3\x84' != '\xc4').

Encoding to UTF

>>> u8 = v.decode("iso-8859-1").encode("utf-8")
>>> u8
'\xc3\x84pple'    # convert iso-8859-1 to unicode to utf-8

>>> tell_me_about(u8)
(<type 'str'>, '\xc3\x84pple')

>>> u16 = v.decode('iso-8859-1').encode('utf-16')
>>> tell_me_about(u16)
(<type 'str'>, '\xff\xfe\xc4\x00p\x00p\x00l\x00e\x00')

>>> tell_me_about(u8.decode('utf8'))
(<type 'unicode'>, u'\xc4pple')

>>> tell_me_about(u16.decode('utf16'))
(<type 'unicode'>, u'\xc4pple')

Relationship between unicode and UTF and latin1

>>> print u8
Äpple             # printing utf-8 - because of the encoding we now know
                  # how to print the characters

>>> print u8.decode('utf-8') # printing unicode
Äpple

>>> print u16     # printing 'bytes' of u16
???pple

>>> print u16.decode('utf16')
Äpple             # printing unicode

>>> v == u8
False             # v is a iso8859-1 string; u8 is a utf-8 string

>>> v.decode('iso8859-1') == u8
False             # v.decode(...) returns unicode

>>> u8.decode('utf-8') == v.decode('latin1') == u16.decode('utf-16')
True              # all decode to the same unicode memory representation
                  # (latin1 is iso-8859-1)

Unicode Exceptions

 >>> u8.encode('iso8859-1')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 0:
  ordinal not in range(128)

>>> u16.encode('iso8859-1')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0:
  ordinal not in range(128)

>>> v.encode('iso8859-1')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 0:
  ordinal not in range(128)

One would get around these by converting from the specific encoding (latin-1, utf8, utf16) to unicode e.g. u8.decode('utf8').encode('latin1').

So perhaps one could draw the following principles and generalizations:

  • a type str is a set of bytes, which may have one of a number of encodings such as Latin-1, UTF-8, and UTF-16
  • a type unicode is a set of bytes that can be converted to any number of encodings, most commonly UTF-8 and latin-1 (iso8859-1)
  • the print command has its own logic for encoding, set to sys.stdout.encoding and defaulting to UTF-8
  • One must decode a str to unicode before converting to another encoding.

Of course, all of this changes in Python 3.x.

Hope that is illuminating.

Further reading

And the very illustrative rants by Armin Ronacher:

ggplot2: sorting a plot

Here are a couple of ways.

The first will order things based on the order seen in the data frame:

x$variable <- factor(x$variable, levels=unique(as.character(x$variable)) )

The second orders the levels based on another variable (value in this case):

x <- transform(x, variable=reorder(variable, -value) ) 

Java: convert seconds to minutes, hours and days

Have a look at the class

org.joda.time.DateTime

This allows you to do things like:

old = new DateTime();
new = old.plusSeconds(500000);
System.out.println("Hours: " + (new.Hours() - old.Hours()));

However, your solution probably can be simpler:

You need to work out how many seconds in a day, divide your input by the result to get the days, and subtract it from the input to keep the remainder. You then need to work out how many hours in the remainder, followed by the minutes, and the final remainder is the seconds.

This is the analysis done for you, now you can focus on the code.

You need to ask what s/he means by "no hard coding", generally it means pass parameters, rather than fixing the input values. There are many ways to do this, depending on how you run your code. Properties are a common way in java.

Array Length in Java

if you mean by "logical size", the index of array, then simply int arrayLength = arr.length-1; since the the array index starts with "0", so the logical or "array index" will always be less than the actual size by "one".

What and where are the stack and heap?

Stack:

  • Stored in computer RAM just like the heap.
  • Variables created on the stack will go out of scope and are automatically deallocated.
  • Much faster to allocate in comparison to variables on the heap.
  • Implemented with an actual stack data structure.
  • Stores local data, return addresses, used for parameter passing.
  • Can have a stack overflow when too much of the stack is used (mostly from infinite or too deep recursion, very large allocations).
  • Data created on the stack can be used without pointers.
  • You would use the stack if you know exactly how much data you need to allocate before compile time and it is not too big.
  • Usually has a maximum size already determined when your program starts.

Heap:

  • Stored in computer RAM just like the stack.
  • In C++, variables on the heap must be destroyed manually and never fall out of scope. The data is freed with delete, delete[], or free.
  • Slower to allocate in comparison to variables on the stack.
  • Used on demand to allocate a block of data for use by the program.
  • Can have fragmentation when there are a lot of allocations and deallocations.
  • In C++ or C, data created on the heap will be pointed to by pointers and allocated with new or malloc respectively.
  • Can have allocation failures if too big of a buffer is requested to be allocated.
  • You would use the heap if you don't know exactly how much data you will need at run time or if you need to allocate a lot of data.
  • Responsible for memory leaks.

Example:

int foo()
{
  char *pBuffer; //<--nothing allocated yet (excluding the pointer itself, which is allocated here on the stack).
  bool b = true; // Allocated on the stack.
  if(b)
  {
    //Create 500 bytes on the stack
    char buffer[500];

    //Create 500 bytes on the heap
    pBuffer = new char[500];

   }//<-- buffer is deallocated here, pBuffer is not
}//<--- oops there's a memory leak, I should have called delete[] pBuffer;

Capturing window.onbeforeunload

The reason why nothing happens when you use 'alert()' is probably as explained by MDN: "The HTML specification states that calls to window.alert(), window.confirm(), and window.prompt() methods may be ignored during this event."

But there is also another reason why you might not see the warning at all, whether it calls alert() or not, also explained on the same site:

"... browsers may not display prompts created in beforeunload event handlers unless the page has been interacted with"

That is what I see with current versions of Chrome and FireFox. I open my page which has beforeunload handler set up with this code:

window.addEventListener
('beforeunload'
, function (evt)
  { evt.preventDefault();
    evt.returnValue = 'Hello';
    return "hello 2222"
  }
 );

If I do not click on my page, in other words "do not interact" with it, and click the close-button, the window closes without warning.

But if I click on the page before trying to close the window or tab, I DO get the warning, and can cancel the closing of the window.

So these browsers are "smart" (and user-friendly) in that if you have not done anything with the page, it can not have any user-input that would need saving, so they will close the window without any warnings.

Consider that without this feature any site might selfishly ask you: "Do you really want to leave our site?", when you have already clearly indicated your intention to leave their site.

SEE: https://developer.mozilla.org/en-US/docs/Web/Events/beforeunload