[R] counting missing values

[Peter Dalgaard BSA]

Torsten Hothorn <Torsten.Hothorn at rzmail.uni-erlangen.de> writes:

> > Hello R lovers
> > I have written a little cute function to count the number of missing value
> > per row in a matrix and return the percentage of missing value
> >
> 
> R> M <- matrix(rnorm(25), ncol=5)
> R> diag(M) <- NA
> R> M[2,3] <- NA
> R> apply(M, 2, function(x) sum(is.na(x)))/ncol(M)
> [1] 0.2 0.2 0.4 0.2 0.2
> 
> the percentage of missing values per row...

Or:

> apply(is.na(M), 2, mean)
[1] 0.2 0.2 0.4 0.2 0.2

(Actually, that's the proportions. ...*100 for percentages)

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
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