Homework? We don't do homework here. -- Bert
On Mon, May 27, 2013 at 8:24 AM, Estigarribia, Bruno <estig...@email.unc.edu> wrote: > Hello all, > > I have 4 matrices with 3 columns each (different number of rows though). I > want to find a function that returns all possible 3-place vectors > corresponding to the sum by columns of picking one row from matrix 1, one > from matrix 2, one from matrix 3, and one from matrix 4. So basically, all > possible ways of picking one row from each matrix and then sum their > columns to obtain a 3-place vector. > Is there a way to use expand.grid and reduce to obtain this result? Or am > I on the wrong track? > Thank you, > Bruno > PS:I believe I have given all relevant info. I apologize in advance if my > question is ill-posed or ambiguous. > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.