Hi, I'm trying to take a matrix such as
[,1] [,2] [,3] [,4] [,5] [1,] 2 7 2 7 9 [2,] 10 10 6 8 6 [3,] 1 9 7 2 0 and generate a new matrix which contains only the unique values in each row: [,1] [,2] [,3] [,4] [,5] [1,] 2 7 9 NA NA [2,] 10 6 8 NA NA [3,] 1 9 7 2 0 My problem is that I can use apply(matrix,MARGIN=1,FUN=unique) to find the unique values, but this leaves me with a list with arrays of different length: > x <- apply(peaks,MARGIN=1,FUN=unique) [[1]] [1] 2 7 9 [[2]] [1] 10 6 8 [[3]] [1] 1 9 7 2 0 and using do.call("rbind",x) recycles the values of the shorter vectors instead of filling them with NA: > do.call("rbind",x) [,1] [,2] [,3] [,4] [,5] [1,] 2 7 9 2 7 [2,] 10 6 8 10 6 [3,] 1 9 7 2 0 So, I'd like to either take every element of the list and extend it with NAs to the length of the longest element, or rbind every element where missing places are filled with NAs instead of recycled values. Is this possible? Of course, the solution is trivial using a loop, but I'm trying to avoid this. Thanks for any suggestions. ______________________________________________ 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.