From: Berton Gunter <gunter.berton_at_gene.com>

Date: Fri 03 Jun 2005 - 05:07:04 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Jun 03 05:17:39 2005

Date: Fri 03 Jun 2005 - 05:07:04 EST

Not an answer, but a note. Encoding the mean temperature as the circle
radius is a bad idea: the eye perceives the area and so the radius^2, thus
the perceived effect is the square of the actual temperature effect (Howard
Wainer once referrred to this as "goosing up the effect by squaring the
eyeball.") . You should encode the sqrt of the temperature as the radius so
that the area is proportional to temperature. Details matter in graphical
perception.

- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA

"The business of the statistician is to catalyze the scientific learning process." - George E. P. Box

> -----Original Message-----

*> From: r-help-bounces@stat.math.ethz.ch
**> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of
**> Jennifer.Morin@colorado.edu
**> Sent: Thursday, June 02, 2005 11:57 AM
**> To: r-help@stat.math.ethz.ch
**> Subject: [R] Adding a legend to a symbol plot
**>
**> I have created a symbol plot with circles that represent the
**> mean temperature
**> at lat/lon locations over the United States. The radius of the circle
**> corresponds to the mean temperature. I would like to add a legend that
**> identifies a range of temperatures (e.g. 0-10, 10-20, etc)
**> with circles of the
**> appropriate radii next to them. I've read the manual on how
**> to add a legend,
**> and I'm fine with adding one to the plot. However, I cannot
**> get circles of
**> different sizes to come up next to the ranges in my legend.
**> All that is coming
**> up are circles of all the same radius. In looking at the R
**> manual, it appears
**> that in order to get the right radius for the circles, I have
**> to use the "pch"
**> parameter in the "legend" command, but I'm unclear on how I
**> should define this
**> parameter. Can anyone help?
**>
**> thanks,
**> Jennifer Morin
**>
**> ______________________________________________
**> R-help@stat.math.ethz.ch mailing list
**> https://stat.ethz.ch/mailman/listinfo/r-help
**> PLEASE do read the posting guide!
**> http://www.R-project.org/posting-guide.html
**>
*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Jun 03 05:17:39 2005

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