[R] 2d plot with modification of plotting symbol to indicate third dimension.

[Greg Snow]

Look at the symbols function for some options of doing what you suggest (you can also do a search for "bubble plot" for a couple of other implementations).  If you want to go a bit further than what symbols does for you then look at the my.symbols function in the TeachingDemos package.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of John Sorkin
> Sent: Wednesday, January 12, 2011 12:19 PM
> To: r-help at r-project.org
> Subject: [R] 2d plot with modification of plotting symbol to indicate
> third dimension.
> 
> I would like to plot 3-dimensional data on a two-dimensional scatter-
> plot.
> Is there a way I can automatically modify the plot symbol (e.g.
> changing size or color) to indicate the value of a third variable? E.g.
> How can I plot weight vs. age and indicate the value of muscle mass for
> each value weight-age pair by making the plot point proportional to the
> subject's muscle mass?
> Thanks,
> John
> 
> 
> John David Sorkin M.D., Ph.D.
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
> 
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