Question

I have a dataframe that originated from an excel file. It has the usual headers above the columns but some of the columns have % signs in them which I want to remove.

Searching stackoverflow gives some nice code for removing percentages from matrices, Any way to edit values in a matrix in R?, which did not work when I tried to apply it to my dataframe

as.numeric(gsub("%", "", my.dataframe))

instead it just returns a string of “NA”s with a warning message explaining that they were introduced by coercion. When I applied,

gsub("%", "", my.dataframe))

I got the values in “c(…)” form, where the … represent numbers followed by commas which was reproduced for every column that I had. No % was in evidence; if I could just put this back together … I’d be cooking.

Any help greatfully received, thanks.

Answer 1

Based on @Arun’s comment and imaging how your data.frame looks like:

> DF <- data.frame(X = paste0(1:5,'%'), 
                   Y = paste0(2*(1:5),'%'),
                   Z = 3*(1:5), stringsAsFactors=FALSE )

> DF # this is how I imagine your data.frame looks like
   X   Y  Z
1 1%  2%  3
2 2%  4%  6
3 3%  6%  9
4 4%  8% 12
5 5% 10% 15

> # Using @Arun's suggestion
> (DF2 <- data.frame(sapply(DF, function(x) as.numeric(gsub("%", "", x)))))
  X  Y  Z
1 1  2  3
2 2  4  6
3 3  6  9
4 4  8 12
5 5 10 15

I added as.numeric in sapply call for the resulting cols to be numeric, if I don’t use as.numeric the result will be factor. Check it out using sapply(DF2, class)