Here is a slight simplification to the first line based on the fact that na.locf works column by column:
mat <- t(na.locf(t(mydata), fromLast = TRUE, na.rm = FALSE)) On Mon, Apr 5, 2010 at 1:46 PM, Peter Ehlers <ehl...@ucalgary.ca> wrote: > If I understand correctly what you want (according to your loop), > you could use the na.locf function in pkg:zoo. > > library(zoo) > mat <- t(apply(mydata, 1, na.locf, fromLast=TRUE, na.rm=FALSE)) > dat <- as.data.frame(mat) ## since apply returns a matrix > > -Peter Ehlers > > On 2010-04-05 10:52, Anna Stevenson wrote: >> >> #I wish to find the "next non-NA" value within each row of a data-frame. >> #e.g. I have a data frame mydata. Rows 1, 2& 3 have soem NA values. >> >> mydata<- data.frame(matrix(seq(20*6), 20, 6)) >> mydata[1,3:5]<- NA >> mydata[2,2:3]<- NA >> mydata[2,5]<- NA >> mydata[3,6]<- NA >> mydata[1:3,] >> >> #this loop accomplishes the task; I am tryign toi learn a "better" way >> >> for(i in (ncol(mydata)-1):1 ){ >> mydata[,i]<- ifelse(is.na(mydata[,i])==TRUE,mydata[,i+1],mydata[,i]) >> } >> >> mydata[1:3,] >> #Thank you. I appreciate the help. >> >> >> >> >> [[alternative HTML version deleted]] >> >> >> >> >> ______________________________________________ >> 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. > > -- > Peter Ehlers > University of Calgary > > ______________________________________________ > 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.