I converted the whole data frame to character by using as.matrix And then using a posting that explained how to get the naming conventions back (which had been lost when converting to matrix)
Anything that I did not list with the id's it insisted in including them with the measured variables. In other words it would not let me drop. despite melted<-melt(BigDF, id=c("SAMPLE_ID","ASSAY_ID"), measured=c("GENOTYPE_ID","DESCRIPTION")) unique(melted$variable) [1] CUSTOMER PROJECT PLATE EXPERIMENT CHIP WELL_POSITION GENOTYPE_ID DESCRIPTION ENTRY_OPERATOR [10] INTERACT PLATEc Levels: CUSTOMER PROJECT PLATE EXPERIMENT CHIP WELL_POSITION GENOTYPE_ID DESCRIPTION ENTRY_OPERATOR INTERACT PLATEc I should have only got GENOTYPE_ID and DESCRIPTION "hadley wickham" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] >> nr.attempts >> <-aggregate(RawSeq$GENOTYPE_ID,list(sample=RawSeq$SAMPLE_ID,assay=RawSeq$ASSAY_ID),length) >> This was simply to figure out how many times the same piece of >> information >> had been obtained. I ran out of patience. It took beyond forever and >> tapply >> did not perform much better. The reshape package did not help - it >> implied >> one was out of luck if the data was not numeric. All of my data is >> character >> or factor. > > The reshape package will work if all your data is numeric, or all of > it is character - it doesn't work with a mix. I will try and make > this more clear in the documentation. > However, depending on the size and structure of your data it may not > be any faster than tapply or aggregate. > > Hadley > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.