[R] matrix operation

Tuszynski, Jaroslaw W. JAROSLAW.W.TUSZYNSKI at saic.com
Mon Oct 10 14:22:11 CEST 2005


 There a re a few ways to do it without loop. Here is one:
 
 dat = matrix(runif(100), 50,2)
 dat[,1] = dat[,1] >= dat[,2]

 Jarek 
====================================================\==== 
 Jarek Tuszynski, PhD.                           o / \ 
 Science Applications International Corporation  <\__,|  
 (703) 676-4192                                   ">  \ 
 Jaroslaw.W.Tuszynski at saic.com                     `   \ 



-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] 
Sent: Friday, October 07, 2005 6:02 PM
To: r-help at stat.math.ethz.ch
Subject: [R] matrix operation

Hello:

I have a matrix 'dat' with 2 columns.

I have the following code:

for (i in 1:nrows(dat))
{
  if (dat[i,1] < dat[i,2])
    {
      dat[i,2]<-0
    }

   else
   {
     dat[i,2]<-1
   }


Is there a way to accomplish this without the for loop?

Thank you.

-Dhiren

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