Try this: diag(A[c(1,3),c(2,3)])
2010/3/12 Nils Rüfenacht <nils.ruefena...@bluewin.ch>: > Dear all! > > I'm trying to get multiple values from a matrix by using a single command. > > Given a matrix A > > A <- matrix(seq(1,9),nrow=3,ncol=3) > > How can I get e.g. the values A[1,2] = 4 and A[3,3] = 9 with a single > command and without using any loop? My first idea was to generate a row- and > a column vector for the indices, i.e. c(1,3) indicating row number 1 (for > A[1,2]) and row number 3 (for A[3,3]) and similar for column-indices. Then > I've tried to call > > A[c(1,3),c(2,3)] > > but instead of 4 , 9 the result is > > [,1] [,2] > [1,] 4 7 > [2,] 6 9 > > Any suggestions? > > Regards, Nils > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.
