On Apr 20, 2012, at 4:57 AM, Dimitris Rizopoulos wrote:
try this:
x <- 1:3
y <- matrix(1:12, ncol = 3, nrow = 4)
y * rep(x, each = nrow(y))
Another way with a function specifically designed for that purpose:
sweep(y, 2, x, "*")
--
David.
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
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--
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/
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.