[R] vector replacement 1/0 to P/A

[Chuck Cleland]

On 8/17/2009 10:22 AM, Lana Schaffer wrote:
> Hi,
> Can someone suggest an efficient way to substitute a vector/matrix
> which contains 1's and 0's to P's and A's (resp.)?
> Thanks,
> Lana

  Here is one approach:

mymat <- matrix(rbinom(15, 1, .5), ncol=3)

mymat
     [,1] [,2] [,3]
[1,]    1    0    0
[2,]    0    0    1
[3,]    1    0    1
[4,]    0    1    0
[5,]    1    1    0

mymat[] <- sapply(mymat, function(x){ifelse(x == 1, 'P', ifelse(x == 0,
'A', NA))})

mymat
     [,1] [,2] [,3]
[1,] "P"  "A"  "A"
[2,] "A"  "A"  "P"
[3,] "P"  "A"  "P"
[4,] "A"  "P"  "A"
[5,] "P"  "P"  "A"

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-- 
Chuck Cleland, Ph.D.
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