Thanks to Michael, Josh and Jorge - Problem fixed. Michael's suggestion was what I needed, but I wouldn't have ever conceptualized it that way, and Jorge showed me how simple the function could be (at this hour, I was imagining it would be more work). Thanks guys. Bryan
On 11/28/10 11:03 PM, "Michael Sumner" <mdsum...@gmail.com> wrote: > vec is being recycled column wise, so you can repeat each element the > required number of times: > > tmp[p,] <- rep(vec, each = length(p)) > > There's many ways to achieve this though, so it depends on what other > variations you might want to deal with. > > Cheers, Mike. > > On Mon, Nov 29, 2010 at 2:53 PM, Bryan Hanson <han...@depauw.edu> wrote: >> Hello Folks. This must be a silly question with a (not) obvious (to me) >> answer. >> >> Consider this: >> >> tmp <- matrix(1:200, nrow = 20) >> vec <- 300:309 >> >> tmp[9,] <- vec # replacing one row works fine >> >> p <- c(3, 11, 17) >> tmp[p,] <- vec >> # replacing multple rows pastes the values down a column and recycles vec. >> >> What I want to do is replace multiple rows simultaneously at once. I >> suppose I can write a function, but this seems pretty fundamental so I feel >> I must be missing some obvious alternative. I'm feeling like I'm in the >> Inferno! >> >> TIA. Bryan >> ************* >> Bryan Hanson >> Professor of Chemistry & Biochemistry >> DePauw University, Greencastle IN USA >> >>> sessionInfo() >> R version 2.12.0 (2010-10-15) >> Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit) >> >> locale: >> [1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8 >> >> attached base packages: >> [1] splines datasets tools grid grDevices graphics utils >> stats >> [9] methods base >> >> other attached packages: >> [1] survival_2.35-8 gridExtra_0.7 GGally_0.2.2 xtable_1.5-6 >> [5] mvbutils_2.5.1 ggplot2_0.8.8 proto_0.3-8 reshape_0.8.3 >> [9] ChemoSpec_1.46 seriation_1.0-2 colorspace_1.0-1 TSP_1.0-1 >> [13] R.utils_1.5.3 R.oo_1.7.4 R.methodsS3_1.2.1 rgl_0.92.794 >> [17] lattice_0.19-13 mvoutlier_1.4 plyr_1.2.1 >> RColorBrewer_1.0-2 >> [21] chemometrics_1.0 som_0.3-5 robustbase_0.5-0-1 rpart_3.1-46 >> [25] pls_2.1-0 pcaPP_1.8-3 mvtnorm_0.9-92 nnet_7.3-1 >> [29] mclust_3.4.6 MASS_7.3-8 lars_0.9-7 gclus_1.3 >> [33] cluster_1.13.1 e1071_1.5-24 class_7.3-2 >> >> ______________________________________________ >> 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.