Hi Matthew and Steve, thank you both for your suggestions. I had not used the basename function before and that was what was keeping me from moving forward along with my coding.
As Matthew has suggested I made a post at http://stackoverflow.com/questions/18165373/interpolation-of-grouped-data-using-data-table with the remaining question that I have. This is my revised code: big <- lapply(sitefiles,freadDataRatingDepotFiles) big <- rbindlist(big) setnames(big,c("y", "shift", "x", "stor", "site_no")) big[, y:=as.numeric(y)] big[, x:=as.numeric(x)] big[, shift:=as.numeric(shift)] big[, stor:=NULL] big <- na.omit(big) big[,y:=y+shift] big[,shift:=NULL] big[, site_no := sub(".exsa.rdb", "", basename(site_no), fixed=TRUE)] setkey(big, site_no) big <- big[aimjoin] Once again, thank you both for your advice and suggestions. Irucka -- View this message in context: http://r.789695.n4.nabble.com/subset-between-data-table-list-and-single-data-table-object-tp4673202p4673496.html Sent from the datatable-help mailing list archive at Nabble.com. _______________________________________________ datatable-help mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help
