Dear r-help contributors, I have two questions:
first: I have a matrix A and a vector B. I want to make a new matrix C, which is made of the rows of A having a value included in B. Second: I have two matrixes A and B, of different dimensions. B has unique values in column 2 and A has not unique values on column 2. I want to merge this two matrixes by the values in the columns 2 of B and 2 of A in such a way that the resulting matrix will be C: A: 1 2 2 2 3 3 4 3 5 4 6 4 7 5 8 5 B: 1 2 x c d 2 3 y f g C: 1 2 x c d 2 2 x c d 3 3 y f g 4 3 y f g 5 4 NA NA 6 4 NA NA 7 5 NA NA 8 5 NA NA Can you help me? Many thanks in advance. [[alternative HTML version deleted]] ______________________________________________ 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.