Hi again, I understood what you guys explained... But, there isn't a way to do a multiplication of matrix with a FOR command or otherelse where one o my dimension is ONE... Well, as my data file is small, I did the procedure at the excel... But, this is not the good procedure... Thanks, Marcio
Uwe Ligges-3 wrote: > > > > MarcioRibeiro wrote: >> Hi listers, >> I am having some trouble in a matrix multiplication... >> I have already checked some posts, but I didn't find my problem... >> I have the following code... >> But I am not getting the right multiplication... >> I checked the dimension and they are fine... >> >> id_y <- array(1:10,dim=c(2,1,5)) >> id_yt<-aperm(id_y,c(2,1,3)) >> m_id<-array(dim=c(dim(id_y)[1],dim(id_y)[1],dim(id_y)[3])) >> for (i in 1:dim(id_y)[3]){ >> m_id[,,i]<-id_y[,,i]%*%id_yt[,,i] >> } >> m_id >> >> > > > Due to indexing, you are loosing dimensions. > The problem is that you expect to *loose exactly one* dimension in this > case (hence drop = FALSE won't be of help right away). Hence it might be > a good idea to know what you are going to have exactly at the end (as > in- and output). > > Uwe Ligges > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Matrix-multiplication---code-problem-tp22835003p22850519.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.