Hello, Instead of 'sum' use 'mean'
ok <- apply(tbl, 2, function(x) mean(!is.na(x)) >= 0.5) cor(tbl[, ok], use="pairwise.complete.obs") Hope this helps, Rui Barradas Em 29-05-2012 10:03, jeff6868 escreveu:
Hi everybody. I'm trying to do a correlation matrix in a list of files. Each file contains 2 columns: "capt1" and "capt2". For the example, I merged all in one data.frame. My data also contains many missing data. The aim is to do a correlation matrix for the same data for course (one correlation matrix for capt1 and another for capt2). For the moment, I have a correlation matrix which works (for capt1 or capt2). But correlation coefficients of this matrix are calculated whatever the number of missing data per column. What I want to do is to have exactly the same correlation matrix, but only with coefficients calculated with at least half of non missing data in the column (in the example, at least 5 non NA values out of 10). table<- data.frame(ST1_capt1=rnorm(1:10),ST1_capt2=c(1,2,3,4,NA,NA,7:9,NA), ST2_capt1=c(NA,NA,NA,NA,NA,6:10),ST2_capt2=c(21,NA,NA,NA,25:30), ST3_capt1=c(1,NA,NA,4:10),ST3_capt2=c(NA,NA,NA,NA,NA,NA,NA,NA,NA,NA)) cormatrix<- cor(table[,c(1,3,5)],use="pairwise.complete.obs") To solve this problem, I think it would be useful to use a code like this before calculating the correlation matrix: if(sum(!is.na(table[1:10,]))>=5) then calculate the correlation coefficient, and else (if less than 5 non-NA values) put NA in the correlation matrix. I'm trying to combinate all this stuff but it doesn't work. Could somebody help me to do this? Many thanks! -- View this message in context: http://r.789695.n4.nabble.com/correlation-matrix-only-if-enough-non-NA-values-tp4631666.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
