[R] Conditional Matrices

[Ales Ziberna]

#M1 = first matrix
#M2 = second matrix

M2[M1==0]<-NA

----- Original Message ----- 
From: "ISAIAH SHALWITZ" <shalwitz.1 at osu.edu>
To: <r-help at stat.math.ethz.ch>
Sent: Tuesday, August 16, 2005 5:00 AM
Subject: [R] Conditional Matrices


> This seems like a simple problem but I can't figure it out:
>
> I have two identical DIMENSION matrices.  Both contain only binary values 
> NOT identical between matrices.  What I want to do: If in cell (1,1) the 
> value in the first matrix (x) equals 1, then I keep the value in cell 
> (1,1) in the second matrix (y).  If in cell (1,1) the value in the first 
> matrix (x) equals 0, then I change the value in cell (1,1) in the second 
> matrix (y)to missing (NA).  Repeat for every pair of cells (coordinates of 
> the paired cells always match).
>
> Please help.
>
> I
>
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