Hi, The program below work very well.
(snps = c('rs621782_G', 'rs8087639_G', 'rs8094221_T', 'rs7227515_A', 'rs537202_C')) Selec = todos[ , colnames(todos) %in% snps] head(Selec) But, I have a data set with 1.000 columns and I need extract 70 to use (like snps in command above). This 70 snps are in a file. So I create a file to extract them with (mod5.sig = with(mod5, data.frame(snps = SNP[pvalor < 5e-8]))) str(mod5.sig) (snps = (mod5.sig)) The structure is: 'data.frame': 76 obs. of 1 variable: $ snps: Factor w/ 220 levels "rs10058955_A",..: 89 59 88 73 40 35 97 55 87 204 ... But it doesn't work. The output is: > Selec = todos[ , colnames(todos) %in% snps] > head(Selec) data frame with 0 columns and 6 rows What's is wrong? Thanks a lot, --------------------------------------------- Silvano Cesar da Costa Universidade Estadual de Londrina Centro de Ciências Exatas Departamento de EstatÃstica Fone: (43) 3371-4346 ______________________________________________ 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.