Hi matrix is virtually a vector so you can find index of values of x and add those values to propper places in ax
ax <- a idx <- which(!is.na(x)) ax[idx] <- x[idx] ax [,1] [,2] [,3] [1,] 3 2 1 [2,] 4 2 2 [3,] 5 5 2 Regards Petr r-help-boun...@r-project.org napsal dne 13.07.2009 11:31:12: > > Hi, > > I have two matricies a and x: > > a<-matrix(c(3,4,5,2,3,4,1,1,2), nrow=3, ncol=3) > > [,1] [,2] [,3] > [1,] 3 2 1 > [2,] 4 3 1 > [3,] 5 4 2 > > x<-matrix(c(3, NA, NA, NA, 2, 5, NA, 2, 2), nrow=3, ncol=3) > > [,1] [,2] [,3] > [1,] 3 NA NA > [2,] NA 2 2 > [3,] NA 5 2 > > I wish to combine these two into one matrix using the values from x where x > has values, and values from a where x has NA's, giving a new matrix which > would look like this: > > ax<-matrix(c(3,4,5,2,2,5,1,2,2), nrow=3, ncol=3) > > [,1] [,2] [,3] > [1,] 3 2 1 > [2,] 4 2 2 > [3,] 5 5 2 > > I want an automatic way of doing this as my actual application is a much larger matrix. > > Thanks in advance > > Tom > > > _________________________________________________________________ > > [[elided Hotmail spam]] > > > [[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. ______________________________________________ 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.