Use 'which(...arr.ind=T)' > x.1 [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 6 10 3 4 10 7 9 8 4 10 [2,] 8 7 4 7 4 8 3 NA 3 4 [3,] 7 7 10 10 3 5 3 2 2 2 [4,] 3 4 5 10 10 2 6 9 4 5 [5,] 3 5 9 5 6 NA 3 NA 6 7 [6,] 9 6 10 5 10 4 2 10 NA 5 [7,] 5 2 5 10 3 7 6 4 6 8 [8,] 2 6 1 8 9 2 7 8 3 8 [9,] 9 1 4 9 8 10 2 NA 1 7 [10,] 2 4 8 7 NA 4 3 NA 5 5 > x.4 [1] 5.5 5.5 5.0 7.5 8.0 5.0 3.0 8.0 4.0 6.0 > Med <- apply(x.1, 2, median, na.rm=T) # get median > Ind <- which(is.na(x.1), arr.ind=T) # determine which are NA > x.1[Ind] <- Med[Ind[,'col']] # replace with median > x.1 [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 6 10 3 4 10 7 9 8 4 10 [2,] 8 7 4 7 4 8 3 8 3 4 [3,] 7 7 10 10 3 5 3 2 2 2 [4,] 3 4 5 10 10 2 6 9 4 5 [5,] 3 5 9 5 6 5 3 8 6 7 [6,] 9 6 10 5 10 4 2 10 4 5 [7,] 5 2 5 10 3 7 6 4 6 8 [8,] 2 6 1 8 9 2 7 8 3 8 [9,] 9 1 4 9 8 10 2 8 1 7 [10,] 2 4 8 7 8 4 3 8 5 5 >
On 9/27/05, Weiwei Shi <[EMAIL PROTECTED]> wrote: > > Hi, > I have the following codes to replace missing using median, assuming > missing > only occurs on continuous variables: > > trn1<-read.table('trn1.fv', header=F, na.string='.', sep='|') > > # median > m.trn1<-sapply(1:ncol(trn1), function(i) median(trn1[,i], na.rm=T)) > > #replace > trn2<-trn1 > for (each in 1:nrow(trn1)){ > index.missing=which(is.na(trn1[each,])) > trn2[each,]<-replace(trn1[each,], index.missing, m.trn1[index.missing]) > } > > > Anyone can suggest some ways to improve it since replacing 10 takes 1.5sec: > > system.time(for (each in 1:10){index.missing=which(is.na(trn1[each,])); > trn2[each,]<-replace(trn1[each,], index.missing, m.trn1[index.missing]);}) > [1] 1.53 0.00 1.53 0.00 0.00 > > > Another general question is > are there some packages in R doing missing handling? > > Thanks, > > -- > Weiwei Shi, Ph.D > > "Did you always know?" > "No, I did not. But I believed..." > ---Matrix III > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > -- Jim Holtman Cincinnati, OH +1 513 247 0281 What the problem you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html