Hi Sandy, I don't have an answer to your question, but wanted to share another possibility:
ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 1, position = position_identity(), alpha=.5) Best, Ista On Wed, Dec 1, 2010 at 6:09 AM, Small Sandy (NHS Greater Glasgow & Clyde) <sandy.sm...@nhs.net> wrote: > Thanks Thierry > > Using the position_dodge positioning option ought to work but there is > something wrong with the scaling when the binwidth is not = 1. > You can begin to see this with the example I sent: > > If you do > ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 1, > position = position_dodge()) > > You get the interleaved histogram you would expect > Similarly if you do: > ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 2, > position = position_dodge()) > The histogram produced is reasonable: however > > However if you do: > ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 1, > position = position_dodge(width=0.99)) > > The position of first bin which goes from 0-2 appears to start at about 0.2 > (I accept that there is some "white space" to the left of this) while the > position of the last bin (16-18) appears to start at about 15.8, so the whole > histogram seems to be wrongly compressed into the scale. In my real data > which has potentially 250 bins the problem becomes much more pronounced. Has > any one else noticed this? Is there a work around? > > I could just use a frquency polygon as suffested by Hadley but on a 6 x 3 > facet grid solid blocks are considerably more eye catching. > > Thanks for any help > Sandy > > Sandy Small > Clinical Physicist > NHS Forth Valley > (Tel: 01324567002) > and > NHS Greater Glasgow and Clyde > (Tel: 01412114592) > ________________________________________ > From: ONKELINX, Thierry [thierry.onkel...@inbo.be] > Sent: 30 November 2010 14:57 > To: Small Sandy (NHS Greater Glasgow & Clyde); r-help@r-project.org > Subject: RE: [R] ggplot2 histograms > > Dear Sandy, > > Have a look at the position argument of geom_histogram. > > ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 1, > position = position_dodge()) > ggplot(data=dafr, aes(x = d1, fill=d2)) + geom_histogram(binwidth = 1, > position = position_dodge(width = 0.5), alpha = 0.5) > > Best regards, > > Thierry > > ------------------------------------------------------------------------ > ---- > ir. Thierry Onkelinx > Instituut voor natuur- en bosonderzoek > team Biometrie & Kwaliteitszorg > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > > Research Institute for Nature and Forest > team Biometrics & Quality Assurance > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > > tel. + 32 54/436 185 > thierry.onkel...@inbo.be > www.inbo.be > > To call in the statistician after the experiment is done may be no more > than asking him to perform a post-mortem examination: he may be able to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The plural of anecdote is not data. > ~ Roger Brinner > > The combination of some data and an aching desire for an answer does not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > >> -----Oorspronkelijk bericht----- >> Van: r-help-boun...@r-project.org >> [mailto:r-help-boun...@r-project.org] Namens Small Sandy (NHS >> Greater Glasgow & Clyde) >> Verzonden: dinsdag 30 november 2010 15:37 >> Aan: r-help@r-project.org >> Onderwerp: [R] ggplot2 histograms >> >> Hi >> >> With ggplot2 I can very easily create beautiful histograms >> but I would like to put two histograms on the same plot. The >> histograms may be over-lapping. >> When they are overlapping the bars are shown on top of each >> other (so that the overall height is the sum of the two). Is >> there any way to get them to display overlapping (with >> smaller value in front, larger value behind) so that the >> overall height is equal to the height of the largest value >> >> The following demonstrates the problem (there is probably a >> simple way to generate the sequence in d1 but I don't know it >> and just threw this together quickly) >> d1<-c(1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,6,6,6,6,7,7,7,8,8,9,6,7,7, > 8,8,8,9,9,9,9,10,10,10,10,10,11,11,11,11,12,12,12,13,13,14,15,15,16,16,1 > 6,17,17,17,17,18,18,18,18,18) >> >> d2<-c(rep("a",25), rep("b",39)) >> dafr<-data.frame(d1,d2) >> >> library(ggplot) >> qplot(d1, data=dafr, fill=d2, geom='histogram', binwidth = 1) >> >> Many thanks for any help >> Sandy >> >> Sandy Small >> Clinical Physicist >> NHS Forth Valley >> and >> NHS Greater Glasgow and Clyde >> >> >> ************************************************************** >> ****************************************************** >> >> This message may contain confidential information. If >> yo...{{dropped:24}} >> >> ______________________________________________ >> 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 message may contain confidential information. If you are not the > intended recipient please inform the > sender that you have received the message in error before deleting it. > Please do not disclose, copy or distribute information in this e-mail or take > any action in reliance on its contents: > to do so is strictly prohibited and may be unlawful. > > Thank you for your co-operation. > > NHSmail is the secure email and directory service available for all NHS staff > in England and Scotland > NHSmail is approved for exchanging patient data and other sensitive > information with NHSmail and GSi recipients > NHSmail provides an email address for your career in the NHS and can be > accessed anywhere > For more information and to find out how you can switch, visit > www.connectingforhealth.nhs.uk/nhsmail > > ______________________________________________ > 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. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ 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.
