[R] Adding data to a histogram

[January Weiner]

Hello,

I'd like to overlay two histograms for comparison. I know that this
can be done, in fact I have done it myself several times. But right
now I can't neither remember nor find any documentation.

Is there anywhere a comprehensible guide for making graphics / plots
with R? I know there are plenty of good tutorials, and I have read
many of them, but a nice ref card or something similar would be very
helpful (I started writing up one myself, but maybe there is somewhere
already an existing one).

Regards,
January

-- 
------------ January Weiner 3  ---------------------+---------------
Division of Bioinformatics, University of Muenster  |  Schloßplatz 4
(+49)(251)8321634                                   |  D48149 Münster
http://www.uni-muenster.de/Biologie.Botanik/ebb/    |  Germany