[R] Replacing 0s with NA

[Chuck Cleland]

On 6/12/2009 4:55 AM, Christine Griffiths wrote:
> Hello
> 
> I have a dataset in which I would like to replace 0s with NAs. There is
> a lot of information on how to replace NAs with 0, but I have struggled
> to find anything with regards to doing the reverse. Any recommendations
> would be great.

X <- as.data.frame(matrix(sample(0:9, 100, replace=TRUE), ncol=10))

X
   V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
1   7  5  8  9  6  6  4  8  5   8
2   6  2  9  6  8  5  9  1  1   3
3   4  1  5  8  9  5  3  2  1   4
4   4  8  7  7  4  1  1  4  9   8
5   9  2  5  8  4  8  4  8  6   0
6   3  4  2  8  2  0  6  4  8   5
7   3  5  0  2  7  7  9  9  3   1
8   7  3  3  4  8  3  9  2  7   1
9   4  7  9  1  5  4  8  2  1   9
10  7  7  6  1  0  9  0  5  7   0

X[] <- lapply(X, function(x){replace(x, x == 0, NA)})

X
   V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
1   7  5  8  9  6  6  4  8  5   8
2   6  2  9  6  8  5  9  1  1   3
3   4  1  5  8  9  5  3  2  1   4
4   4  8  7  7  4  1  1  4  9   8
5   9  2  5  8  4  8  4  8  6  NA
6   3  4  2  8  2 NA  6  4  8   5
7   3  5 NA  2  7  7  9  9  3   1
8   7  3  3  4  8  3  9  2  7   1
9   4  7  9  1  5  4  8  2  1   9
10  7  7  6  1 NA  9 NA  5  7  NA

> Cheers
> Christine
> 
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-- 
Chuck Cleland, Ph.D.
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