try this: mat <- matrix(rnorm(20), 5, 4, dimnames = list(letters[1:5], LETTERS[1:4])) mat[sample(20, 4)] <- NA
ind <- which(is.na(mat), arr.ind = TRUE) mat cbind(RowName = rownames(mat)[ind[, 1]], ColName = colnames(mat)[ind[, 2]]) I hope it helps. Best, Dimitris On 10/8/2010 7:09 AM, Data Analytics Corp. wrote:
Hi, Suppose I have a 3X4 matrix with row names TL, JAR and TM and column names A, B, C, D. The cell in the first row, third column has an NA. I want to find the row and column NAMES corresponding to that cell with the NA. Obviously, I want to extend this to any matrix of any size that has one or more cells with NAs. Any suggestions? Thanks, Walt ________________________ Walter R. Paczkowski, Ph.D. Data Analytics Corp. 44 Hamilton Lane Plainsboro, NJ 08536 ________________________ (V) 609-936-8999 (F) 609-936-3733 w...@dataanalyticscorp.com www.dataanalyticscorp.com _____________________________________________________
-- Dimitris Rizopoulos Assistant Professor Department of Biostatistics Erasmus University Medical Center Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands Tel: +31/(0)10/7043478 Fax: +31/(0)10/7043014 Web: http://www.erasmusmc.nl/biostatistiek/ ______________________________________________ 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.