Thomas, You could perhaps do a tad better by simply adding a right-hand-side axis using axis():
axis(4, at=c(4.3,4.0,3.7, 3.3,3.0,2.7, 2.3,2.0,1.7, 1.3,1.0,0.7), labels=c('A+','A','A-','B+','B','B-','C+','C','C-','D+','D','D-'), las=1) That way you have both numeric and grade scales. if you want a left-hand grade scale only, first suppress the axes in the barplot using axes=FALSE, and then add the axes using axis(1) and axis(2,..) with the ... as above. Incidentally, I'm not sure I'd have converted your numbers that way, but if it's worked it's worked. Steve E >>> Thomas Levine <thomas.lev...@gmail.com> 02/28/10 12:44 AM >>> I have grades data. I read them from a csv in letter-grade format. I then converted them to levels levels(grades$grade)=c('A+','A','A-','B+','B','B-','C+','C','C-','D+','D','D-') And then to numbers grades$gp=grades$grade levels(grades$gp)=c(4.3,4.0,3.7, 3.3,3.0,2.7, 2.3,2.0,1.7, 1.3,1.0,0.7) grades$gp=as.numeric(as.character(grades$gp)) And I'm plotting them in a barplot barplot(gp[order(gp)],width=n[order(gp)],ylab="Class Median Grade",xlab="Class, scaled to number of students in the class",main="Class Median Grades for Cornell University weighted by class size") I would like to change the scale on the bar graph such that it reads c('A+','A','A-','B+','B','B-','C+','C','C-','D+','D','D-') in the locations c(4.3,4.0,3.7, 3.3,3.0,2.7, 2.3,2.0,1.7, 1.3,1.0,0.7) Any ideas? Tom ______________________________________________ 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. ******************************************************************* This email and any attachments are confidential. Any use...{{dropped:8}} ______________________________________________ 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.