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. 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.
