1

I need to duplicate those levels whose frequency in my factor variable called groups is less than 500.

> head(groups)
[1] 0000000 1000000 1000000 1000000 0000000 0000000
75 Levels: 0000000 0000001 0000010 0000100 0000110 0001000 0001010 0001100 0001110 0010000 0010010 0010100 0010110 ... 1111110

For example:

> table(group)
group
0000000 0000001 0000010 0000100 0000110 0001000 0001010 0001100 0001110 0010000 0010010 0010100 0010110 0011000 0011010 0011100 
  58674       6    1033     654     223    1232      31     222      17     818     132      32      15      42       9       9 
0011110 0100000 0100001 0100010 0100100 0100101 0100110 0101000 0101010 0101100 0101110 0110000 0110010 0110100 0110110 0111000 
      1   10609       1     487      64       1      58     132      11      12       3     142      27       9       7      11 
0111010 0111100 0111110 1000000 1000001 1000010 1000011 1000100 1000101 1000110 1001000 1001001 1001010 1001100 1001110 1010000 
      5       1       2   54245      10    1005       1     329       1     138     573       1      31      71      11     969 
1010010 1010100 1010110 1011000 1011010 1011100 1011110 1100000 1100001 1100010 1100011 1100100 1100110 1101000 1101010 1101011 
    147      29      21      63      15      10       4   14161       6     770       1     142      96     260      23       1 
1101100 1101110 1110000 1110001 1110010 1110100 1110110 1111000 1111010 1111100 1111110 
     34      16     439       2     103      13      26      36      13       8       5

Groups 0000001, 0000110, 0001010, 0001100... must be duplicated up to 500.

The ideal would be to have a "sample balanced data" of groups that duplicate those levels often less than 500 and penalize the rest (Levels more than 500 frequency) until reaching 500.

Mario M.
  • 802
  • 11
  • 26

1 Answers1

1

We can use rep on the levels of 'group' for the desired 'n'

factor(rep(levels(group), each = n))

If we need to use the table results as well

factor(rep(levels(group), table(group) + n-table(group)) )

Or with pmax

factor(rep(levels(group), pmax(n, table(levels(group)))))

data

set.seed(24)
group <- factor(sample(letters[1:6], 3000, replace = TRUE))
n <- 500
akrun
  • 874,273
  • 37
  • 540
  • 662