Your code looks fine to me. What did t2pd look like? I tried reproducing the problem in R-3.2.4(Revised) and everything worked (although the output of str() looked a bit different - perhaps you have an old version of R)
> df <- data.frame(TE=1:10, TR=101:110, Command=c("pd_local_abdomen_t2","knee_pd_t1_localize","PD_localize_tre_t2","t2_localize_PD")[rep(1:4,len=10)]) > str(df) 'data.frame': 10 obs. of 3 variables: $ TE : int 1 2 3 4 5 6 7 8 9 10 $ TR : int 101 102 103 104 105 106 107 108 109 110 $ Command: Factor w/ 4 levels "knee_pd_t1_localize",..: 2 1 3 4 2 1 3 4 2 1 > subset(df,grepl("t2",Command) & grepl("pd",Command)) TE TR Command 1 1 101 pd_local_abdomen_t2 5 5 105 pd_local_abdomen_t2 9 9 109 pd_local_abdomen_t2 > subset(df,grepl("t2",Command,ignore.case=TRUE) & grepl("pd",Command,ignore.case=TRUE)) TE TR Command 1 1 101 pd_local_abdomen_t2 3 3 103 PD_localize_tre_t2 4 4 104 t2_localize_PD 5 5 105 pd_local_abdomen_t2 7 7 107 PD_localize_tre_t2 8 8 108 t2_localize_PD 9 9 109 pd_local_abdomen_t2 Bill Dunlap TIBCO Software wdunlap tibco.com On Sat, Apr 30, 2016 at 2:38 PM, ch.elahe via R-help <r-help@r-project.org> wrote: > Hi all, > > I have one factor variable in my df and I want to extract the names from > it which contain both "t2" and "pd": > > 'data.frame': 36919 obs. of 162 variables > $TE :int 38,41,11,52,48,75,..... > $TR :int 100,210,548,546,..... > $Command :factor W/2229 levels > "_localize_PD","_localize_tre_t2","_abdomen_t1_seq","knee_pd_t1_localize","pd_local_abdomen_t2"... > > I have tried this but I did not get result: > > t2pd=subset(df,grepl("t2",Command) & grepl("pd",Command)) > > > does anyone know how to apply AND in grepl? > > Thanks > Elahe > > ______________________________________________ > 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.