>-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED]] On Behalf Of Liaw, Andy >Sent: Wednesday, February 05, 2003 7:00 AM >To: '[EMAIL PROTECTED]' >Subject: [R] barplot default colors > > >Dear R-help, > >Can some one explain why barplot() uses changing colors in the >bars by default? I should think that most of the time when >people draw barplots, they want the bars to be in the same >color. (At least that's what I'd expect. The first time I >used barplot() in R, I was shocked to see the >colors.) As an example, one example in ?layout draws a >scatterplot with histograms drawn on the margins. The >histograms were drawn by barplot(), and, IMHO, look rather >hideous in the colors. > >Regards, >Andy > >Andy I. Liaw, PhD >Biometrics Research Phone: (732) 594-0820 >Merck & Co., Inc. Fax: (732) 594-1565 >P.O. Box 2000, RY84-16 Rahway, NJ 07065 >mailto:[EMAIL PROTECTED]
Andy, This is an extrapolation beyond known data by me, but I would suspect that one plausible reason is that since barplot can do grouped bars and stacked bars, the original author decided to set a single default multiple color vector for all cases. This would be one approach rather than checking to see what type of barplot was being drawn and using a single color for the scenario you are using or a multiple color vector for grouped/stacked bars. It is obviously easy enough to add 'col = "color"' to the barplot() arguments to use a single color of your choosing or an alternate multiple color vector. To change the default behavior now would likely break other code in use. My two cents.... Regards, Marc Schwartz ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
