Dear Mr. Dimitris Rizopoulos, Thanks a lot for your great help. It worked nicely. I couldn't have figured it out. Thanks again.
Regards Vincy --- On Fri, 4/20/12, Dimitris Rizopoulos <d.rizopou...@erasmusmc.nl> wrote: From: Dimitris Rizopoulos <d.rizopou...@erasmusmc.nl> Subject: Re: [R] Matrix multiplication by multple constants To: "Vincy Pyne" <vincy_p...@yahoo.ca> Cc: r-help@r-project.org Received: Friday, April 20, 2012, 8:57 AM try this: x <- 1:3 y <- matrix(1:12, ncol = 3, nrow = 4) y * rep(x, each = nrow(y)) I hope it helps. Best, Dimitris On 4/20/2012 10:51 AM, Vincy Pyne wrote: > Dear R helpers > > Suppose > > x<- c(1:3) > > y<- matrix(1:12, ncol = 3, nrow = 4) > >> y > [,1] [,2] [,3] > [1,] 1 5 9 > [2,] 2 6 10 > [3,] 3 7 11 > [4,] 4 8 12 > > I wish to multiply 1st column of y by first element of x i.e. 1, 2nd column > of y by 2nd element of x i.e. 2 an so on. Thus the resultant matrix should be > like > >> z > > [,1] [,2] [,3] > > [1,] 1 10 27 > > [2,] 2 12 30 > > [3,] 3 14 33 > > [4,] 4 16 36 > > > When I tried simple multiplication like x*y, y is getting multiplied > column-wise > >> x*z > [,1] [,2] [,3] > [1,] 1 5 9 > [2,] 4 12 20 > [3,] 9 21 33 > [4,] 16 32 48 > > > Kindly guide > > Regards > > Vincy > > [[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. -- Dimitris Rizopoulos Assistant Professor Department of Biostatistics Erasmus University Medical Center Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands Tel: +31/(0)10/7043478 Fax: +31/(0)10/7043014 Web: http://www.erasmusmc.nl/biostatistiek/ [[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.
