(Private) On Sat, May 11, 2013 at 3:24 PM, Tom Roche <tom_ro...@pobox.com> wrote: > > Tom Roche Wed, 08 May 2013 20:38:12 -0400 >>> I have two spatial grids defined the same way (i.e., same number of >>> rows and columns--and dimensions, both 2D). Wherever both > >>> * the value of an element i,j in the first grid is NA >>> * the value of element i,j in the second grid is !NA > >>> I want to copy the value from grid2[i,j] to grid1[i,j]. > > Bill Dunlap Thu, 9 May 2013 04:02:18 +0000 >> [assuming] that the dimensions of the grids are the same[:] > >> grid1 <- c(1,2,NA,3,NA) >> grid2 <- c(101,102,103,104,NA) >> shouldCopy <- is.na(grid1) & !is.na(grid2) >> grid1[shouldCopy] <- grid2[shouldCopy] >> grid1 > [1] 1 2 103 3 NA > > Thanks! I had no idea bitwise booleans (which are what come to my mind > when I see '&' or '|') were overloaded thus.
But you would have if you had read the Intro to R tutorial that ships with R, or other online tutorial of your choice. Please make the effort. -- Bert Much more convenient than > *apply semantics for this task! Variants of the above now in use @ > > https://bitbucket.org/tlroche/aqmeii_ag_soil/src/c5fc8038281d0d5683d45bc797c59fc4b0a55c6b/combine_EDGAR_and_EPIC_emissions.r?at=master > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.