ValueError setting an array element with a sequence

Question

This Python code   import numpy as p  def firstfunction        UnFilteredDuringExSummaryOfMeansArray          MeanOutputHeader   TestID   ConditionName   FilterType   RRMean   HRMean                          dZdtMaxVoltageMean   BZMean   ZXMean   LVETMean   Z0Mean                          StrokeVolumeMean   CardiacOutputMean   VelocityIndexMean       dataMatrix   BeatByBeatMatrixOfMatrices column      roughTrimmedMatrix   p array dataMatrix 1  1 17         trimmedMatrix   p array roughTrimmedMatrix dtype p float64    ERROR THROWN HERE       myMeans   p mean trimmedMatrix axis 0 dtype p float64      conditionMeansArray    TestID testCondition  UnfilteredBefore  myMeans 3   myMeans 4                               myMeans 6   myMeans 9   myMeans 10   myMeans 11   myMeans 12                              myMeans 13   myMeans 14   myMeans 15       UnFilteredDuringExSummaryOfMeansArray append conditionMeansArray      secondfunction UnFilteredDuringExSummaryOfMeansArray      return  def secondfunction UnFilteredDuringExSummaryOfMeansArray       RRDuringArray   p array UnFilteredDuringExSummaryOfMeansArray dtype p float64  1  3      return  firstfunction     Throws this error message   File  mypath mypythonscript py   line 3484  in secondfunction RRDuringArray   p array UnFilteredDuringExSummaryOfMeansArray dtype p float64  1  3  ValueError  setting an array element with a sequence    Can anyone show me what to do to fix the problem in the broken code above so that it stops throwing an error message     EDIT  I did a print command to get the contents of the matrix  and this is what it printed out   UnFilteredDuringExSummaryOfMeansArray is        TestID    ConditionName    FilterType    RRMean    HRMean    dZdtMaxVoltageMean    BZMean    ZXMean    LVETMean    Z0Mean    StrokeVolumeMean    CardiacOutputMean    VelocityIndexMean     u HF101710    PreEx10SecondsBEFORE    UnfilteredBefore   0 90670000000000006  66 257731979420001  1 8305673000000002  0 11750000000000001  0 15120546389880002  0 26870546389879996  27 628261216480002  86 944190346160013  5 767261352345999  0 066259118585869997    u HF101710    25W10SecondsBEFORE    UnfilteredBefore   0 68478571428571422  87 727887206978565  2 2965444125714285  0 099642857142857144  0 14952476549885715  0 24916762264164286  27 010483303721429  103 5237336525  9 0682762747642869  0 085022572648242867    u HF101710    50W10SecondsBEFORE    UnfilteredBefore   0 54188235294117659  110 74841107829413  2 6719262705882354  0 077705882352917643  0 15051306356552943  0 2282189459185294  26 768787504858825  111 22827075238826  12 329456404418824  0 099814258468417641    u HF101710    75W10SecondsBEFORE    UnfilteredBefore   0 4561904761904762  131 52996981880955  3 1818159523809522  0 074714285714290493  0 13459344175047619  0 20930772746485715  26 391156337028569  123 27387909873812  16 214243779323812  0 1205685359981619     Looks like a 5 row by 13 column matrix to me  though the number of rows is variable when different data are run through the script   With this same data that I am adding in this   EDIT 2  However  the script is throwing an error   So I do not think that your idea explains the problem that is happening here   Thank you  though   Any other ideas     EDIT 3   FYI  if I replace this problem line of code       RRDuringArray   p array UnFilteredDuringExSummaryOfMeansArray dtype p float64  1  3    with this instead       RRDuringArray   p array UnFilteredDuringExSummaryOfMeansArray  1  3    Then that section of the script works fine without throwing an error  but then this line of code further down the line   p ylim  5 RRDuringArray min   1 5 RRDuringArray max      Throws this error   File  mypath mypythonscript py   line 3631  in CreateSummaryGraphics   p ylim  5 RRDuringArray min   1 5 RRDuringArray max    TypeError  cannot perform reduce with flexible type   So you can see that I need to specify the data type in order to be able to use ylim in matplotlib  but yet specifying the data type is throwing the error message that initiated this post

User · Accepted Answer

From the code you showed us  the only thing we can tell is that you are trying to create an array from a list that isn t shaped like a multi-dimensional array   For example  numpy array   1 2    2  3  4      or  numpy array   1 2    2   3  4       will yield this error message  because the shape of the input list isn t a  generalised   box  that can be turned into a multidimensional array   So probably UnFilteredDuringExSummaryOfMeansArray contains sequences of different lengths   Edit  Another possible cause for this error message is trying to use a string as an element in an array of type float   numpy array  1 2   abc    dtype float    That is what you are trying according to your edit   If you really want to have a NumPy array containing both strings and floats  you could use the dtype object  which enables the array to hold arbitrary Python objects   numpy array  1 2   abc    dtype object    Without knowing what your code shall accomplish  I can t judge if this is what you want

User · Answer

When the shape is not regular or the elements have different data types  the dtype argument passed to np array only can be object  import numpy as np    arr1   np array   10  20     30    40    dtype np float32     error arr2   np array   10  20     30    40       OK  and the dtype is object arr3   np array   10  20     hello          OK  and the dtype is also object

User · Answer

In my case  the problem was with a scatterplot of a dataframe X     ax scatter X   0  X   1  c colors             cmap CMAP  edgecolor  k   s 40    c y   0     ValueError  setting an array element with a sequence   Fix with  toarray    colors    br  y   label binarize y  classes   Irrelevant   Relevant    ax scatter X   0  toarray   X   1  toarray   c colors            cmap CMAP  edgecolor  k   s 40

User · Answer

In my case   I got this Error in Tensorflow   Reason was i was trying to feed a array with different length or sequences    example    import tensorflow as tf  input x   tf placeholder tf int32  None None      word embedding   tf get variable  embeddin  shape  len vocab   110  dtype tf float32 initializer tf random uniform initializer -0 01 0 01    embedding look tf nn embedding lookup word embedding input x   with tf Session   as tt      tt run tf global variables initializer         a b tt run  word embedding embedding look  feed dict  input x example array       print b    And if my array is    example array     1 2 3   1 2     Then i will get error    ValueError  setting an array element with a sequence    but if i do padding then    example array     1 2 3   1 2 0     Now it s working

User · Answer

The Python ValueError    ValueError  setting an array element with a sequence    Means exactly what it says  you re trying to cram a sequence of numbers into a single number slot   It can be thrown under various circumstances    1   When you pass a python tuple or list to be interpreted as a numpy array element   import numpy  numpy array  1 2 3                  good  numpy array  1   2 3                Fail  can t convert a tuple into a numpy                                      array element   numpy mean  5  6 7                  good  numpy mean  5 tuple range 2         Fail  can t convert a tuple into a numpy                                      array element   def foo        return 3 numpy array  2  foo                 good   def foo        return  3 4  numpy array  2  foo                 Fail  can t convert a list into a numpy                                      array element   2   By trying to cram a numpy array length   1 into a numpy array element   x   np array  1 2 3   x 0    np array  4            good    x   np array  1 2 3   x 0    np array  4 5          Fail  can t convert the numpy array to fit                                into a numpy array element   A numpy array is being created  and numpy doesn t know how to cram multivalued tuples or arrays into single element slots   It expects whatever you give it to evaluate to a single number  if it doesn t  Numpy responds that it doesn t know how to set an array element with a sequence

User · Answer

for those who are having trouble with similar problems in Numpy  a very simple solution would be   defining dtype object when defining an array for assigning values to it  for instance   out   np empty like lil img  dtype object

User · Answer

In my case  I had a nested list as the series that I wanted to use as an input  First check  If df  nestedList   0   outputs a list like  1 2 3   you have a nested list  Then check if you still get the error when changing to input df  nestedList   0   Then your next step is probably to concatenate all nested lists into one unnested list  using  item for sublist in df  nestedList   for item in sublist   This flattening of the nested list is borrowed from How to make a flat list out of list of lists

User · Answer

In my case  the problem was another  I was trying convert lists of lists of int to array  The problem was that there was one list with a different length than others  If you want to prove it  you must do   print  i for i x in enumerate list  if len x     560     In my case  the length reference was 560

[python] ValueError: setting an array element with a sequence

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