Message-ID: <Pine.A41.4.61b.0503101238190.126942@homer05.u.washington.edu>
Date: 2005-03-10T20:41:07Z
From: Thomas Lumley
Subject: Transparent colors OR two series on one histogram
In-Reply-To: <4230AAB5.5030407@soton.ac.uk>
On Thu, 10 Mar 2005, Nathaniel Street wrote:
> Hi,
>
> I want to be able to plot a single histogram of a measured trait with trait
> values from two conditions on the same histogram to allow easy comparison.
>
> I have previously done this in excel by plotting the two series on a single
> bargraph having calculated frequencies in bins. You then get one condition
> plotted immediately to the right of the other. I hope that makes sense?
>
> I don't know if this is possible in R?
You can do it for bar plots, but not for histograms. Look at
barplot(beside=TRUE)
> If not, I could plot the second one on top of the first i.e.
>
> hist(x)
> hist(y,add=TRUE)
>
> but i would need to set one as having a semi-transparent color so that where
> the two sets of are plotted on top of each other, you can see the frequency
> of the first series 'behind' the second.
Semitransparent colors are available for the pdf() and quartz() devices.
They were described by Paul Murrell in R News Vol 4 No 2.
-thomas