Hi Jim, Rui and William; I do appreciate for your explanations and help. These are very helpful. Regards,
Hayrettin On Tue, Dec 6, 2016 at 4:06 PM, Jim Lemon <drjimle...@gmail.com> wrote: > Hi Greg, > What is happening is easy to see: > > ph<-matrix(sample(1:100,40),ncol=4) > colnames(ph)<-c("M1","X1","X2","X3") > ph[sample(1:10,3),1]<-NA > ph > M1 X1 X2 X3 > [1,] 34 98 3 35 > [2,] 13 66 74 68 > [3,] NA 22 99 79 > [4,] 94 6 80 36 > [5,] 18 9 16 65 > [6,] NA 29 56 90 > [7,] 41 23 7 55 > [8,] 100 93 71 70 > [9,] NA 61 8 57 > [10,] 25 4 47 60 > # get a logical vector showing which rows contain NA > miss <- apply(is.na(ph[,c("M1","X1","X2","X3")]),1, any) > miss > [1] FALSE FALSE TRUE FALSE FALSE TRUE FALSE FALSE TRUE FALSE > # create a vector of zeros the length of the number of rows > select <- integer(nrow(ph)) > select > [1] 0 0 0 0 0 0 0 0 0 0 > # get the indices for the rows that do _not_ have NAs > select[!miss] <- 1:sum(!miss) > select > [1] 1 2 0 3 4 0 5 6 0 7 > > If this is to select the rows without NAs, it may be easier to do: > > which(!miss) > [1] 1 2 4 5 7 8 10 > > Jim > > > > On Wed, Dec 7, 2016 at 5:18 AM, greg holly <mak.hho...@gmail.com> wrote: > > Dear All; > > > > I am very new in R and try to understand the logic for a program has been > > run sucessfully. Here select[!miss] <- 1:sum(!miss) par is confussing > me. I > > need to understandand the logic behind this commend line. > > > > Thanks in advance for your help, > > > > Greg > > > > > > miss <- apply(is.na(ph[,c("M1","X1","X2","X3")]),1, any) > > select <- integer(nrow(ph)) > > select[!miss] <- 1:sum(!miss) > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.