Dear Dr. Vokey, Here is one approach, although may not be the more efficient:
x <- matrix(1:8, ncol = 4) x # [,1] [,2] [,3] [,4] #[1,] 1 3 5 7 #[2,] 2 4 6 8 t(x[, ncol(x):1]) # [,1] [,2] #[1,] 7 8 #[2,] 5 6 #[3,] 3 4 #[4,] 1 2 leftTranspose <- function(x) t(x[, ncol(x):1]) leftTranspose(x) HTH. Jorge.- On Tue, Oct 22, 2013 at 12:52 PM, Vokey, John <> wrote: > useRs, > I frequently require the following transform of a matrix that I call a > leftTranspose: > > -- transposes x such that the last items of each row become > -- the first items in each column. E.g., > -- a b c d > -- e f g h > -- becomes: > -- d h > -- c g > -- b f > -- a e > > because it is a leftward rotation. I have written my own function, but I > was wondering whether I was reinventing the wheel here. Does such a > transpose already exist in R (or matlab/octave/FreeMat, for that matter)? > > > -- > Please avoid sending me Word or PowerPoint attachments. > See <http://www.gnu.org/philosophy/no-word-attachments.html> > > -Dr. John R. Vokey > > ______________________________________________ > 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. > [[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.
