x <- data.frame(matrix(c(rep(11,4),rep(12,3),rep(13,3),rep(0,3),1,rep(0,4),re p(1,2)),ncol=2))
id.keep <- unique(subset(x,X2>0)$X1) x2 <- subset(x,X1 %in% id.keep) x2 -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Stephan Lindner Sent: Thursday, April 02, 2009 11:26 AM To: r-h...@stat.math.ethz.ch Subject: [R] Selecting all rows of factors which have at least one positive value? Dear all, I'm trying to select from a dataframe all rows which correspond to a factor (the id variable) for which there exists at least one positive value of a certain variable. As an example: x <- data.frame(matrix(c(rep(11,4),rep(12,3),rep(13,3),rep(0,3),1,rep(0,4),re p(1,2)),ncol=2)) > x X1 X2 1 11 0 2 11 0 3 11 0 4 11 1 5 12 0 6 12 0 7 12 0 8 13 0 9 13 1 10 13 1 and I want to select all rows pertaining to factor levels of X1 for which exists at least one "1" for X2. To be clear, I want rows 1:4 (since there exists at least one observation for X1==11 for which X2==1) and rows 8:10 (likewise). It is easy to obtain the corresponding factor levels (i.e., unique(x$X1[x$X2==1])), but I got stalled selecting the corresponding rows. I tried grep, but then I have to loop and concatenate the resulting vector. Any ideas? Thanks a lot! Stephan -- ----------------------- Stephan Lindner University of Michigan ______________________________________________ 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. =================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S. News & World Report (2008). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use\...{{dropped:13}} ______________________________________________ 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.
