search for: negindices

I have a function like this: changedir <- function(dataframe) { dir <- dataframe$dir gc_content <- dataframe$gc_content d <- ifelse(dir == "-", gc_content <- -gc_content,gc_content <- gc_content) return(d) } The goal of this function is to be able to input a data frame like this: > lala dir gc_content 1 + 0.5 2 - 0.5 3 +