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counting missing values

5 messages · vincent.stoliaroff@socgen.com, Uwe Ligges, Torsten Hothorn +2 more

#
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

it takes a lot of time to run with a 1000 rows matrix

I'd like to know if there is a function already implemented to count the
number of occurence of a given values in a vector


For information,
here is the function
count<-0
for (i in 1:nrow(Matrix))
      {
      for (j in 1:ncol(Matrix)) {if (is.na(Matrix[i,j])) count<-count+1}
      Result[i,1]<-((count/(ncol(Matrix)))*100);
      count<-0
      }
Result

thanks for any help
Vincent




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#
vincent.stoliaroff at socgen.com wrote:

            
Well, it's pretty easy to do it:

apply(Matrix, 1, function(x) sum(is.na(x))) / ncol(Matrix) * 100

Uwe Ligges
#
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...

Torsten
#
Torsten Hothorn <Torsten.Hothorn at rzmail.uni-erlangen.de> writes:
Or:
[1] 0.2 0.2 0.4 0.2 0.2

(Actually, that's the proportions. ...*100 for percentages)
#
On Thu, 5 Jun 2003, Uwe Ligges wrote:

            
and

   rowMeans(is.na(Matrix))*100

should be faster

	-thomas