R help - Nov 2008 - comparing matrices using max or min

Dear all,
 
I have 3 matrices with the same dimension, A,B,C and I would like to produce
a matrix D where in each position would retrieve the max(or min) value along
A,B,C taken from the same position.
I guess that apply functions should fit, but for matrices objects I am not
getting it.
 
thanks in advance,
 
Diogo André Alagador

	[[alternative HTML version deleted]]

you just need pmax() or pmin(), e.g., check this:

set.seed(123)
M1 <- matrix(rnorm(20), 4, 5)
M2 <- matrix(rnorm(20), 4, 5)
M3 <- matrix(rnorm(20), 4, 5)

M1; M2; M3
pmax(M1, M2, M3)
pmin(M1, M2, M3)


I hope it helps.

Best,
Dimitris


Diogo Andr? Alagador wrote:
> Dear all,
>  
> I have 3 matrices with the same dimension, A,B,C and I would like to
produce
> a matrix D where in each position would retrieve the max(or min) value
along
> A,B,C taken from the same position.
> I guess that apply functions should fit, but for matrices objects I am not
> getting it.
>  
> thanks in advance,
>  
> Diogo Andr? Alagador
> 
> 	[[alternative HTML version deleted]]
> 
> 
> 
> ------------------------------------------------------------------------
> 
> ______________________________________________
> R-help at 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 Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

#how about this
A <- rnorm(10)
B <- rnorm(10)
C <- rnorm(10)

D <- data.frame(A,B,C)

apply(D, MARGIN=1, FUN=min)

On Thu, Nov 6, 2008 at 10:00 AM, Diogo Andr? Alagador
<mcnda839 at mncn.csic.es> wrote:
> Dear all,
>
> I have 3 matrices with the same dimension, A,B,C and I would like to
produce
> a matrix D where in each position would retrieve the max(or min) value
along
> A,B,C taken from the same position.
> I guess that apply functions should fit, but for matrices objects I am not
> getting it.
>
> thanks in advance,
>
> Diogo Andr? Alagador
>
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at 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.
>
>


-- 
Stephen Sefick
Research Scientist
Southeastern Natural Sciences Academy

Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods.  We are mammals, and have not exhausted the
annoying little problems of being mammals.

								-K. Mullis