CODEWITHSUNDEEP
r
Paolo Lorenzini
Paolo Lorenzini

Reputation: 725

Divide each values in rows of different data frames by values stored in vector

I have two data frames df1 and df2 and they are stored inside a list:

$df1 


column 1.  column  2.     column 3 
       A          a6          1
       B          j7          2
       C          i0          3
       D          b2          4

$df2
    column 1.  column  2.  column 3 
       E          8h          1
       F          4d          2
       G          3n          3
       H          a9          4
       I          5%          5
       L          *9.         6

The data frames have different row numbers and are stored in list1 list1<-(df1,df2)

I would like to divide the last column number 3 which represents the rank by the total number of row (divide each value): The row number information is stored in a vector and it is different from the row numbers of those two data frames because they are a subset of a larger data frame with more rows: vec<-c(10,20)

Output:

$df1 
$df1 nrow = 4
#df1_ALL nrow = 10
column 1.  column  2.  column 3 
   A          a6          1/10
   B          j7          2/10
   C          i0          3/10
   D          b2          4/10
$df2
$df2 nrow=6
$df2_ALL nrow = 20
column 1.  column  2.  column 3 
   E          8h          1/20
   F          4d          2/20
   G          3n          3/20
   H          a9          4/20
   I          5%          5/20
   L          *9.         6/20

I wrote something like this:

list2<-list()

for (i in 1: length(list1)) {
+   list2[[i]]<- sweep(list1[[i]]$column3, 1,vec,'/')
+ }

however is giving me the following error:

Error in array(STATS, dims[perm]) : 'dims' cannot be of length 0
In addition: Warning message:
In sweep(myfiles[[i]]$rank, 1, g1, "/") :
  STATS is longer than the extent of 'dim(x)[MARGIN]'

Any help it would be great, cheers

Upvotes: 3

Views: 85

Answers (1)

akrun
akrun

Reputation: 887008

We loop through the list of datasets, with Map and transform to divide the last column by the number of rows of that dataset stored in a vector ('vec')

Map(function(x, y) transform(x, `column 3` = `column 3`/y), list1, vec)

Upvotes: 2

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