Hi Chris, You can use scale_x_discrete() to manually set the locations of the ticks (the "breaks" argument) and what they are labeled with (the "labels" argument). If you want a third of the the ids (or so) you could do something like:
breaks = factor(bb.res.math$id.bb)[seq(1, length(bb.res.math$id.bb), by = 3)] and just change the sequence to skip as many as you want. Of course, you can fully customize it and manually pick each and every id if you really want. HTH, Josh P.S. There is a mailing list specifically for ggplot2 on google groups. On Sat, Jul 9, 2011 at 7:12 AM, Christopher Desjardins <desja...@umn.edu> wrote: > Hi, > I have the follow ggplot2 code I am running: > > ggplot(data=bb.res.math,aes(x=factor(id.bb),y=bb.math.comb,fill=BB)) + > geom_bar() + facet_grid(BB~.) + scale_fill_brewer(pal="Set1") + ylab("Average > Student Residual (Math)") + xlab("Student ID") > > The number of unique id.bb is 2207 and so my X-axis has a couple of > thousands, indistinguishable tick marks that correspond to each id. I am > wondering if there is a way to suppress these tick marks? > > Here is some test data: > >> test > id.bb bb.res.m bb.math.comb BB > 1 2900 1 -3.0032235 BB > 2 2904 1 -1.8758770 BB > 3 3469 1 0.8182852 BB > 4 4213 1 -2.0660215 Not BB > 5 4215 1 -4.8622086 BB > 6 4395 1 0.8873996 Not BB > >> ggplot(data=test,aes(x=factor(id.bb),y=bb.math.comb,fill=BB)) + geom_bar() + >> facet_grid(BB~.) + scale_fill_brewer(pal="Set1") + ylab("Average Student >> Residual (Math)") + xlab("Student ID") > > > Gives the following graph: > > http://dl.dropbox.com/u/1501309/ggplot2_suppress_ids.pdf > > I'd like to prevent "2900", "2904", "3469", etc. from showing up on the > X-axis. > > Thanks, > Chris > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles https://joshuawiley.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.