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: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Thursday, June 02, 2005 11:57 AM > To: [email protected] > 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 > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
