Gabor, thanks a lot! I removed everything from the work space but the data frame - and then DF[is.na(DF)]<-0 has worked! Thanks a lot! Dimitri
On Mon, Mar 29, 2010 at 8:45 PM, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > Its going to be pretty hard to do anything useful if you can`t even do > simple operations like that without overflowing memory but anyways try > this (untested): > > write.table(DF, "DF.csv", sep = ",", quote = FALSE) > rm(DF) > DF <- read.csv(pipe("sed s/NA/0/g DF.csv")) > > > On Mon, Mar 29, 2010 at 8:33 PM, Dimitri Liakhovitski <ld7...@gmail.com> > wrote: >> Just tried it. It's definitely faster - but I get the same error: >> " Reached total allocation of 1535Mb:" >> >> On Mon, Mar 29, 2010 at 8:27 PM, Gabor Grothendieck >> <ggrothendi...@gmail.com> wrote: >>> See if this works for you: >>> >>> DF[is.na(DF)] <- 0 >>> >>> On Mon, Mar 29, 2010 at 8:21 PM, Dimitri Liakhovitski <ld7...@gmail.com> >>> wrote: >>>> Dear R'ers, >>>> >>>> I have a very large data frame (over 4000 rows and 2,500 columns). My >>>> task is very simple - I have to replace all NAs with a zero. My code >>>> works fine on smaller data frames - but I have to deal with a huge one >>>> and there are many NAs in each column. >>>> R runs out of memory on me ("Reached total allocation of 1535Mb: see >>>> help(memory.size)"). Is there any other, more efficient way of doing >>>> it? >>>> Thanks a lot for any hints! >>>> Dimitri >>>> >>>> >>>> # Building an example frame: >>>> frame<-data.frame(a=rnorm(1:100),b=rnorm(1:100),c=rnorm(1:100),d=rnorm(1:100),e=rnorm(1:100),f=rnorm(1:100),g=rnorm(1:100)) >>>> set.seed(1234) >>>> for(i in names(frame)){ >>>> i.for.NA<-sample(1:100,60) >>>> frame[[i]][i.for.NA]<-NA >>>> } >>>> >>>> # Replacing all NAs in "frame" with zeros - is of course fast in this >>>> example, because this data frame is very small >>>> system.time({ >>>> frame<-lapply(frame,function(x){ >>>> x[is.na(x)]<-0 >>>> return(x) >>>> })}) >>>> >>>> >>>> -- >>>> Dimitri Liakhovitski >>>> Ninah.com >>>> dimitri.liakhovit...@ninah.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. >>>> >>> >> >> >> >> -- >> Dimitri Liakhovitski >> Ninah.com >> dimitri.liakhovit...@ninah.com >> > -- Dimitri Liakhovitski Ninah.com dimitri.liakhovit...@ninah.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.