Hi
> Hi, > > I have a matrix (pwdiff in the example below) with ~480000 rows and 780 > columns. > For each row, I want to get the percentage of columns that have an absolute > value above a certain threshold "t". I then want to allocate that percentage > to matrix 'perc' in the corresponding row. Below is my attempt at doing > this, but it does not work: I get 'replacement has length zero'. Any help > would be much appreciated!! > > perc<-matrix(c(1:nrow(pwdiff))) > for (x in 1:nrow(pwdiff)) > perc[x]<-(((ncol(pwdiff[,abs(pwdiff[x,]>=t)]))/ncol(pwdiff))*100) As > matrix(c(1:nrow(pwdiff))) Error in nrow(pwdiff) : object 'pwdiff' not found > gives an error we cannot directly check your code. >From what you say it seems to me that you want something like rowSums(pwdiff>=t, na.rm=T)/ncol(pwdiff)*100 or maybe rowSums(abs(pwdiff)>=t, na.rm=T)/ncol(pwdiff)*100 but I can be completely wrong. Regards Petr > > I should add that my data has NAs in some rows and not others (but I do not > want to just ignore rows that have NAs) > > Thanks! > > Paul > > -- > View this message in context: http://r.789695.n4.nabble.com/counting- > columns-that-fulfill-specific-criteria-tp3622265p3622265.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
