Get type of all variables

Question

In R  I d like to retrieve a list of global variables at the end of my script and iterate over them  Here is my code   declare a few sample variables a lt -10 b lt - Hello world  c lt -data frame     get all global variables in script and iterate over them myGlobals lt -objects   for i in myGlobals     print typeof i        prints  character      My problem is that typeof i  always returns character even though variable a and c are not character variables  How can I get the original type of variable inside the for loop

User · Answer

lapply your dataframe  class  gives you something like    tikr  1   factor    Date  1   Date    Open  1   numeric    High  1   numeric       etc

User · Answer

You need to use get to obtain the value rather than the character name of the object as returned by ls   x  lt - 1L typeof ls     1   character  typeof get ls      1   integer    Alternatively  for the problem as presented you might want to use eapply   eapply  GlobalEnv typeof   x  1   integer    a  1   double    b  1   character    c  1   list

User · Answer

gt  mtcars   gt          summarise all typeof    gt          gather     key  value 1   mpg double 2   cyl double 3  disp double 4    hp double 5  drat double 6    wt double 7  qsec double 8    vs double 9    am double 10 gear double 11 carb double   I try class and typeof functions  but all fails

User · Answer

Designed to do essentially the inverse of what you wanted  here s one of my toolkit toys     lstype lt -function type  closure    inlist lt -ls  GlobalEnv  if  type   function   type  lt - closure  typelist lt -sapply sapply inlist get  typeof  return names typelist typelist  type

User · Answer

R Rscript doesn t have concrete datatypes  R interpreter has a duck-typing memory allocation system   There is no builtin method to tell you the datatype of your pointer to memory   Duck typing is done for speed  but turned out to be a bad idea because now statements such as  print is integer 5   returns FALSE and is integer as integer 5   returns TRUE   Go figure  The R-manual on basic types  https   cran r-project org doc manuals R-lang html Basic-types The best you can hope for is to write your own function to probe your pointer to memory  then use process of elimination to decide if it is suitable for your needs  If your variable is a global or an object  Your object   needs to be penetrated with get      before you can see inside   Example  a  lt - 10 myGlobals  lt - objects   for i in myGlobals     typeof i           prints character   typeof get i       prints integer    typeof      probes your variable pointer to memory  The R function typeof has a bias to give you the type at maximum depth  for example  library tibble    expression              notes                                  type  ----------------------- -------------------------------------- ---------- typeof TRUE               a single boolean                      logical typeof 1L                 a single numeric with L postfixed     integer typeof  quot foobar quot            A single string in double quotes      character typeof 1                  a single numeric                      double typeof list 5 6 7         a list of numeric                     list typeof 2i                 an imaginary number                   complex  typeof 5   5L             double   integer is coerced           double typeof c                  an empty vector has no type           NULL typeof  5                 a bang before a double                logical typeof Inf                infinity has a type                   double typeof c 5 6 7            a vector containing only doubles      double typeof c c TRUE           a vector of vector of logicals        logical typeof matrix 1 10        a matrix of doubles has a type        list  typeof substr  quot abc quot  2 2   a string at index 2 which is  b  is   character typeof c 5L 6L 7L         a vector containing only integers     integer typeof c NA NA NA         a vector containing only NA           logical typeof data frame         a data frame with nothing in it       list typeof data frame c 3     a data frame with a double in it      list typeof c  quot foobar quot          a vector containing only strings      character typeof pi                 builtin expression for pi             double  typeof 1 66               a single numeric with mantissa        double typeof 1 66L              a double with L postfixed             double typeof c  quot foobar quot          a vector containing only strings      character typeof c 5L  6L           a vector containing only integers     integer typeof c 1 5  2 5         a vector containing only doubles      double typeof c 1 5  2 5         a vector containing only doubles      double typeof c TRUE  FALSE      a vector containing only logicals     logical  typeof factor             an empty factor has default type      integer typeof factor 3 14        a factor containing doubles           integer typeof factor T  F        a factor containing logicals          integer typeof Sys Date           builtin R dates                       double typeof hms  hms 3600      hour minute second timestamp          double typeof c T  F             T and F are builtins                  logical typeof 1 10               a builtin sequence of numerics        integer typeof NA                 The builtin value not available       logical  typeof c list T           a vector of lists of logical          list typeof list c T           a list of vectors of logical          list typeof c T  3 14          a vector of logicals and doubles      double typeof c 3 14   quot foo quot       a vector of doubles and characters    character typeof c  quot foo quot  list T     a vector of strings and lists         list typeof list  quot foo quot  c T     a list of strings and vectors         list typeof TRUE   5L          a logical plus an integer             integer typeof c TRUE  5L  1      The true is coerced to 1              integer typeof c c 2i   TRUE  1   logical coerced to complex            complex typeof c NaN   batman     NaN s in a vector don t dominate      character typeof 5  amp  amp  4             doubles are coerced by order of  amp  amp     logical typeof 8  lt   foobar        string and double is coerced          logical typeof list 4  T   1      a list retains type at every index    double typeof list 4  T   2      a list retains type at every index    logical typeof 2    5             result of exponentiation              double typeof 0E0                exponential lol notation              double typeof 0x3fade            hexidecimal                           double typeof paste 3   3        paste promotes types to string        character typeof 3                 R pukes on unicode                    error typeof iconv  quot a quot    quot latin1 quot    quot UTF-8 quot     UTF-8 characters         character typeof 5    5             result of a comparison                logical  class      probes your variable pointer to memory  The R function class has a bias to give you the type of container or structure encapsulating your types  for example  library tibble    expression            notes                                    class  --------------------- ---------------------------------------- --------- class matrix 1 10        a matrix of doubles has a class        matrix class factor  quot hi quot         factor of items is                     factor class TRUE               a single boolean                       logical class 1L                 a single numeric with L postfixed      integer class  quot foobar quot            A single string in double quotes       character class 1                  a single numeric                       numeric class list 5 6 7         a list of numeric                      list class 2i                 an imaginary                           complex class data frame         a data frame with nothing in it        data frame class Sys Date           builtin R dates                        Date class sapply             a function is                          function class charToRaw  quot hi quot      convert string to raw                  raw class array  quot hi quot          array of items is                      array  class 5   5L             double   integer is coerced           numeric class c                  an empty vector has no class          NULL class  5                 a bang before a double                logical class Inf                infinity has a class                  numeric class c 5 6 7            a vector containing only doubles      numeric class c c TRUE           a vector of vector of logicals        logical  class substr  quot abc quot  2 2   a string at index 2 which is  b  is   character class c 5L 6L 7L         a vector containing only integers     integer class c NA NA NA         a vector containing only NA           logical class data frame c 3     a data frame with a double in it      data frame class c  quot foobar quot          a vector containing only strings      character class pi                 builtin expression for pi             numeric  class 1 66               a single numeric with mantissa        numeric class 1 66L              a double with L postfixed             numeric class c  quot foobar quot          a vector containing only strings      character class c 5L  6L           a vector containing only integers     integer class c 1 5  2 5         a vector containing only doubles      numeric class c TRUE  FALSE      a vector containing only logicals     logical  class factor           an empty factor has default class       factor class factor 3 14      a factor containing doubles             factor class factor T  F      a factor containing logicals            factor class hms  hms 3600    hour minute second timestamp            hms difftime class c T  F           T and F are builtins                    logical class 1 10             a builtin sequence of numerics          integer class NA               The builtin value not available         logical  class c list T           a vector of lists of logical          list class list c T           a list of vectors of logical          list class c T  3 14          a vector of logicals and doubles      numeric class c 3 14   quot foo quot       a vector of doubles and characters    character class c  quot foo quot  list T     a vector of strings and lists         list class list  quot foo quot  c T     a list of strings and vectors         list class TRUE   5L          a logical plus an integer             integer class c TRUE  5L  1      The true is coerced to 1              integer class c c 2i   TRUE  1   logical coerced to complex            complex class c NaN   batman     NaN s in a vector don t dominate      character class 5  amp  amp  4             doubles are coerced by order of  amp  amp     logical class 8  lt   foobar        string and double is coerced          logical class list 4  T   1      a list retains class at every index   numeric class list 4  T   2      a list retains class at every index   logical class 2    5             result of exponentiation              numeric class 0E0                exponential lol notation              numeric class 0x3fade            hexidecimal                           numeric class paste 3   3         paste promotes class to string       character class 3                 R pukes on unicode                   error class iconv  quot a quot    quot latin1 quot    quot UTF-8 quot     UTF-8 characters         character class 5    5             result of a comparison                logical  Get the data storage mode of your variable  When an R variable is written to disk  the data layout changes again  and is called the data s storage mode   The function storage mode      reveals this low level information  see Mode  Class  and Type of R objects  You shouldn t need to worry about R s storage mode unless you are trying to understand delays caused by round trip casts coercions that occur when assigning and reading data to and from disk  Demo  R Rscript gettype your variable   Run this R code then adapt it for your purposes  it ll make a pretty good guess as to what type it is  get type  lt - function variable      sz  lt - as integer length variable    length of your variable    tof  lt - typeof variable              typeof your variable    cls  lt - class variable               class of your variable    isc  lt - is character variable        what is character   has to say about it      d  lt - dim variable                   dimensions of your variable    isv  lt - is vector variable     if  is matrix variable          d  lt - dim t variable                dimensions of your matrix            observations ---- gt  datatype    if  sz gt  1  amp  amp  tof     quot logical quot   amp  amp  cls     quot logical quot   amp  amp  isv    TRUE   return  quot vector of logical quot        if  sz gt  1  amp  amp  tof     quot integer quot   amp  amp  cls     quot integer quot     return  quot vector of integer quot        if  sz  1  amp  amp  tof     quot double quot    amp  amp  cls     quot Date quot     return  quot Date quot        if  sz gt  1  amp  amp  tof     quot raw quot       amp  amp  cls     quot raw quot     return  quot vector of raw quot        if  sz gt  1  amp  amp  tof     quot double quot    amp  amp  cls     quot numeric quot     return  quot vector of double quot        if  sz gt  1  amp  amp  tof     quot double quot    amp  amp  cls     quot array quot     return  quot vector of array of double quot        if  sz gt  1  amp  amp  tof     quot character quot    amp  amp  cls     quot array quot     return  quot vector of array of character quot        if  sz gt  0  amp  amp  tof     quot list quot         amp  amp  cls     quot data frame quot     return  quot data frame quot        if  sz gt  1  amp  amp  isc    TRUE          amp  amp  isv    TRUE   return  quot vector of character quot        if  sz gt  1  amp  amp  tof     quot complex quot      amp  amp  cls     quot complex quot     return  quot vector of complex quot        if  sz  0  amp  amp  tof     quot NULL quot         amp  amp  cls     quot NULL quot     return  quot NULL quot        if  sz gt  0  amp  amp  tof     quot integer quot      amp  amp  cls     quot factor quot     return  quot factor quot        if  sz gt  1  amp  amp  tof     quot double quot       amp  amp  cls     quot numeric quot   amp  amp  isv    TRUE   return  quot vector of double quot        if  sz gt  1  amp  amp  tof     quot double quot       amp  amp  cls     quot matrix quot    return  quot matrix of double quot        if  sz gt  1  amp  amp  tof     quot character quot    amp  amp  cls     quot matrix quot    return  quot matrix of character quot        if  sz gt  1  amp  amp  tof     quot list quot         amp  amp  cls     quot list quot   amp  amp  isv    TRUE   return  quot vector of list quot        if  sz gt  1  amp  amp  tof     quot closure quot      amp  amp  cls     quot function quot   amp  amp  isv    FALSE   return  quot closure function quot        return  quot it s pointer to memory  bruh quot       assert  lt - function a  b      if  a    b        cat  quot P quot           else       cat  quot  nFAIL     Sniff test  n quot        sz  lt - as integer length variable      length of your variable      tof  lt - typeof variable                typeof your variable      cls  lt - class variable                 class of your variable      isc  lt - is character variable          what is character   has to say about it       d  lt - dim variable                     dimensions of your variable      isv  lt - is vector variable       if  is matrix variable            d  lt - dim t variable                      dimensions of your variable             if   is function variable           print paste  quot value    quot   variable   quot   quot                print paste  quot get type said    quot   a   quot   quot         print paste  quot supposed to be    quot   b   quot   quot           cat  quot  nYour pointer to memory has properties  n quot         print paste  quot sz    quot   sz   quot   quot         print paste  quot tof    quot   tof   quot   quot         print paste  quot cls    quot   cls   quot   quot         print paste  quot d    quot   d   quot   quot         print paste  quot isc    quot   isc   quot   quot         print paste  quot isv    quot   isv   quot   quot         quit            these asserts give a sample for exercising the code   assert get type TRUE         quot vector of logical quot     everything is a vector in R by default   assert get type c TRUE       quot vector of logical quot     c   just casts to vector  assert get type c c TRUE     quot vector of logical quot     casting vector multiple times does nothing  assert get type  5           quot vector of logical quot     bang inflicts  not truth-like   assert get type 1L                 quot vector of integer quot      naked integers are still vectors of 1  assert get type c 1L  2L           quot vector of integer quot      Longs are not doubles  assert get type c 1L  c 2L  3L     quot vector of integer quot      nested vectors of integers  assert get type c 1L  c TRUE       quot vector of integer quot      logicals coerced to integer  assert get type c FALSE  c 1L      quot vector of integer quot      logicals coerced to integer  assert get type  quot foobar quot            quot vector of character quot       character here means  string   assert get type c 1L   quot foobar quot      quot vector of character quot       integers are coerced to string  assert get type 5              quot vector of double quot    assert get type 5   5L         quot vector of double quot    assert get type Inf            quot vector of double quot    assert get type c 5 6 7        quot vector of double quot    assert get type NaN              quot vector of double quot    assert get type list 5           quot vector of list quot       your list is in a vector   assert get type list 5 6 7       quot vector of list quot    assert get type c list 5 6 7     quot vector of list quot    assert get type list c 5 6  T    quot vector of list quot       vector of list of vector and logical  assert get type list 5 6 7       quot vector of list quot    assert get type 2i               quot vector of complex quot    assert get type c 2i  3i  4i     quot vector of complex quot    assert get type c                 quot NULL quot    assert get type data frame        quot data frame quot    assert get type data frame 4 5    quot data frame quot    assert get type Sys Date          quot Date quot    assert get type sapply            quot closure function quot    assert get type charToRaw  quot hi quot     quot vector of raw quot    assert get type c charToRaw  quot a quot    charToRaw  quot b quot       quot vector of raw quot    assert get type array 4           quot vector of array of double quot    assert get type array 4 5         quot vector of array of double quot    assert get type array  quot hi quot         quot vector of array of character quot    assert get type factor            quot factor quot    assert get type factor 3 14       quot factor quot    assert get type factor TRUE       quot factor quot    assert get type matrix 3 4 5      quot matrix of double quot    assert get type as matrix 5       quot matrix of double quot    assert get type matrix  quot yatta quot     quot matrix of character quot     I put in a C   Java Python ideology here that gives me the scoop of what the memory most looks like   R triad typing system is like trying to nail spaghetti to the wall   lt - and  lt  lt - will package your matrix to a list when you least suspect    As the old duck-typing saying goes  If it waddles like a duck and if it quacks like a duck and if it has feathers  then it s a duck

User · Answer

You can use class x  to check the variable type  If requirement is to check all variables type of a data frame then sapply x  class  can be used

[r] Get type of all variables

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