I expect the answer to involve manipulating indices. But why do you need to do this? This looks suspiciously like homework, and there is a no-homework policy on this list (see the Posting Guide). --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
"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. ______________________________________________ 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.