In addition to reading Frequently Asked Questions Section 7.31, you should always run your own code before posting. Yours does not work. Spend some time reading one or more of the R tutorials and learn about vectorization. It will save you time and typing. There are many to choose from at
http://cran.r-project.org/other-docs.html Do not try to match decimal values. Instead create an index value that is a character string. Then you can match the character strings: > dat1<-data.frame(x=c(1.0,1.2,3.2,4.0,5.1),y=c(23,17,12,27,8)) > dat2 <- data.frame(x=seq(0.1,6,by=0.1),y=rep(0,60)) # Errors in your code corrected here > dat1$xc <- sprintf("%1.1f", dat1$x, 1) # Create dat1 index value as character > dat2$xc <- sprintf("%1.1f", dat2$x, 1) # Create dat2 index value as character > dat2[match(dat1$xc, dat2$xc),] <- dat1 # update dat2 with dat1 > dat2[dat2$y>0,] # Check the results x y xc 10 1.0 23 1.0 12 1.2 17 1.2 32 3.2 12 3.2 40 4.0 27 4.0 51 5.1 8 5.1 > dat1 x y xc 1 1.0 23 1.0 2 1.2 17 1.2 3 3.2 12 3.2 4 4.0 27 4.0 5 5.1 8 5.1 ------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of jim holtman Sent: Wednesday, July 3, 2013 7:22 AM To: André de Boer Cc: R mailing list Subject: Re: [R] merge dataframes FAQ 7.31 On Wed, Jul 3, 2013 at 7:55 AM, Andri de Boer <rnie...@gmail.com> wrote: > Hello, > > I have two dataframes: > dat1<-data.frame(x=c(1.0,1.2,3.2,4.0,5.1),y=c(23,17,12,27,8)) > dat2<-data.frame(x=seq(0,6,by=0.1),y=rep(0,60))) > > I want to replace the corresponding rows of dat2 with the ones of dat1. > I tried: > > for(i in 1:nrow(dat1)) > { > dat2[dat2$x==dat1[i,1],2]<-dat1[i,2] > } > > But I discovered that not every 5.1 is equal: > > > dat2[52,1][1] 5.1> dat1[5,1][1] 5.1> dat2[52,1]==dat1[5,1][1] FALSE > > > > How to solve this? > > > > Regards, > > Andri > > [[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. > > -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. [[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.
