R, relating columns to row

Question

I have five columns[each column name represents each candidate say..

can1 can2 can3 can4 can5

, each column has binary data(TRUE OR FALSE) and

Answer 1

You could also use a simple mapply for this:

df$new_colmn <- 
mapply(function(x,y) {
  df[x,y]
  },
  1:nrow(df),     #row number
  df$CANDIDATES)  #corresponding candidates column

Essentially for each row (x argument) you return the corresponding candidates column (y argument).

Ouput:

> df
   can1 can2  can3  can4  can5 CANDIDATES new_colmn
1  TRUE TRUE FALSE  TRUE FALSE       can2      TRUE
2 FALSE TRUE FALSE FALSE FALSE       can4     FALSE
3 FALSE TRUE  TRUE FALSE FALSE       can2      TRUE
4  TRUE TRUE FALSE FALSE  TRUE       can1      TRUE