Get column names where dat is equal to

Question

I have a data frame (df) with 7 rows and 4 columns (named c1, c2, c3, c4):

c1  c2  c3  c4
Yes No  Yes No    
Yes Yes No  No    
No  Yes No  No    
Yes No  No         


        

Answer 1

You could try something like:

colnames(df) <- c("c1", "c2", "c3", "c4")

test <- (apply(df,1,function(x) which(x=="Yes")))

df$cols <- lapply(test,names)

This was along the lines of what you were initially trying I think.

To tidy the output you could:

 df$cols <- gsub("c(", "", df$cols, fixed = TRUE)

 df$cols <- gsub(")", "", df$cols, fixed = TRUE)

This removes the c().