From: Peter Dalgaard BSA (p.dalgaard@biostat.ku.dk)
Date: Tue 01 Apr 2003 - 00:56:54 EST
Message-id: <x2adfbfutl.fsf@biostat.ku.dk>
volkswirt@gmx.net writes:
> How can I remove all rows/collumns from a matrix that fulfill a certain
> condition? For instance: remove all negative elements from a [n,1]-matrix.
> I intended to write a function for this aim, but it does not work. Despite
> that it may help to get my point, when I ad it:
>
> kratek<-function(eine)
> {
> halt<-0
> for(index in 1:dim(eine)[1])
> {
> if(eine[(index-halt),1]<=0)
> {
> eine<-eine[-(index-halt),]
> halt<-halt+1
> }
> }
> eine
> }
Like this?
m <- matrix(rnorm(20),ncol=2)
m[6,1]<-NA
m[-which(m[,1]<=0),]
(Notice that this is not the same as m[m[,1]>0,] as soon as NA's are
involved).
-- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907______________________________________________ R-help@stat.math.ethz.ch mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
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