I guess this has a simple solution: I have matrix 'mat1' which has row and column names, e.g.:
A B C row1 0 0 0 row2 0 0 0 .... rown 0 0 0 I have a another matrix 'mat2', essentially a subset of 'mat1' where the rownames are all in 'mat1' e.g.: B row3 5 row8 6 row54 7 I want to insert the values of matrix mat2 for column B (in reality it could be some or all of column names A, B or C, etc.) (same name in both matrices if that matters - rownames of mat2 guaranteed to be in mat1) into matrix mat1 where the rownames match, so final desired result is: matrix mat1: A B C row1 0 0 0 row2 0 0 0 row3 0 5 0 ... row8 0 6 0 ... row54 0 7 0 .. rown 0 0 0 My solution was (along the lines of): mat1[rownames(mat2)%in%rownames(mat1),"B"]=mat2[,"B"] Is there a better way? It doesn't 'feel' right? Thanks - hope I explained it right (its late and I had a little drink about an hour ago,etc....). Martin ______________________________________________ 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.