I have a binary matrix of size N x 300. I then create the following: > set.seed(1234) > (key_file <- sample(letters[1:4], 300, replace=TRUE)) [1] "a" "c" "c" "c" "d" "c" "a" "a" "c" "c" "c" "c" "b" "d" "b" "d" "b" "b" "a" "a" "b" "b" "a" [24] "a" "a" "d" "c" "d" "d" "a" "b" "b" "b" "c" "a" "d" "a" "b" "d" "d" "c" "c" "b" "c" "b" "c" [47] "c" "b" "a" "d" "a" "b" "c" "c" "a" "c" "b" "d" "a" "d" "d" "a" "b" "a" "a" "c" "b" "c" "a" [70] "c" "a" "d" "a" "d" "a" "c" "b" "a" "b" "c" "d" "b" "a" "c" "a" "d" "b" "b" "a" "d" "a" "d" [93] "a" "a" "a" "c" "b" "a" "b" "c" "a" "c" "b" "a" "a" "b" "a" "a" "b" "a" "c" "a" "d" "a" "a" [116] "d" "d" "b" "a" "d" "c" "d" "d" "d" "b" "b" "b" "c" "b" "b" "d" "c" "a" "b" "d" "b" "d" "c" [139] "c" "d" "c" "d" "b" "b" "b" "c" "c" "c" "d" "c" "b" "a" "a" "d" "a" "d" "c" "d" "b" "c" "b" [162] "c" "b" "a" "a" "c" "b" "a" "d" "b" "d" "c" "c" "b" "b" "d" "b" "c" "a" "b" "b" "b" "c" "a" [185] "d" "a" "d" "c" "b" "c" "c" "d" "a" "d" "d" "d" "d" "c" "d" "c" "c" "c" "b" "d" "c" "c" "b" [208] "b" "a" "d" "c" "b" "a" "d" "c" "d" "c" "c" "b" "d" "b" "a" "b" "b" "a" "b" "d" "b" "c" "b" [231] "d" "c" "a" "d" "c" "a" "c" "b" "b" "d" "b" "a" "a" "c" "d" "b" "d" "c" "d" "d" "c" "c" "b" [254] "b" "a" "c" "b" "a" "c" "c" "d" "a" "c" "b" "a" "a" "c" "a" "a" "c" "b" "d" "b" "d" "a" "c" [277] "d" "c" "b" "b" "b" "b" "d" "d" "c" "b" "b" "b" "c" "d" "c" "b" "d" "a" "c" "d" "c" "a" "c" [300] "b"
I now replace all 1's in column 1 with key_file[1], I replace all 1's in column 2 with key_file[2] and so on through column 300. This part is simple. Now, I want to replace the 0's in column 1 with either b,c, or d, but not with an a since that was used to replace the 1's. For column 2 I want to replace all 0's with either a,b, or d but not with c since that was used to replace the 1's. However, I do not want all 0's in column 1 to be the same letter. That is, I would not want them all to be replaced with a 'b'. Rather, I want to randomly recode the 0's as either b,c, or d. So, some 0's will be recoded as b, some as c, and some as d. If I were replacing the zeros with the same letter, this would be a simple ifelse command. But, because I want randomness I'm not sure how I can do this other than a costly loop than goes through the data matrix cell-by-cell and does some replacement. That would be fine, but very time consuming. Does anyone have thoughts on how else I could tackle this? Harold ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
