I have a data frame that is the result of a cast (reshape) operation. I deleted the variable column and tried to melt the resulting data frame. Depending on which method I use to delete the column I get different error messages when melting:
> head(tinfos) vpn group trial_no item relation trial_type rt variable # 1 102 2 1 4351 diag1 distractor 8471 fix_d 27 2 102 2 2 1214 id target 4072 fix_d 17 3 102 2 3 4213 diag1 distractor 7040 fix_d 27 4 102 2 4 1314 id target 4370 fix_d 15 5 102 2 5 2655 vert distractor 4397 fix_d 17 6 102 2 6 3322 horiz distractor 6132 fix_d 26 > tinfos$variable <- NULL > melt(tinfos) Error: id variables not found in data: variable Or: > tinfos2 <- tinfos[,-match("variable",names(tinfos))] > melt(tinfos2) Error in `rownames<-`(`*tmp*`, value = character(0)) : attempt to set rownames on object with no dimensions In addition: Warning messages: 1: In `[<-.factor`(`*tmp*`, ri, value = c(8471L, 4072L, 7040L, 4370L, : invalid factor level, NAs generated 2: In `[<-.factor`(`*tmp*`, ri, value = c(0L, 0L, 1L, 0L, 0L, 0L, 0L, : invalid factor level, NAs generated I figure there must be some internal inconsistency in the data frame after deletion. Does anybody have an idea how to fix that? Thanks! Titus ______________________________________________ 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.