Thanks Paul, I was trying to get the function for getMass to input into another column into a data set using R code:
FakeCompounds$Molecule <- with(FakeCompounds, getMolecule(Molecular.Formula)) showData(FakeCompounds, placement='-20+200', font=getRcmdr('logFont'), maxwidth=80, maxheight=30) FakeCompounds$Molecular.Mass <- with(FakeCompounds, getMass(Molecular.Formula)) which gave me the response error: [24] ERROR: $ operator is invalid for atomic vectors Which I didn't quite understand in the context of Rdisop, does it only allow for one variable at a time? So I tried to create a loop, ending up with: c(getFormula(getMolecule("CH3")),getFormula(getMolecule("CH2")))->B i<-1 for (i in 1:length(B)){G[i]<-getMass(B[i])} but I still get the same error: [25] ERROR: $ operator is invalid for atomic vectors The final goal is to have a list that can calculate molecular mass from a list of chemical formulas. Any help? I'm not sure if this is a problem only related to Rdisop or not. Thanks a lot! Matt -- View this message in context: http://r.789695.n4.nabble.com/Need-to-Write-a-Code-that-can-find-the-molecular-weight-of-various-compounds-tp4342874p4365836.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.