On 04/10/2012 04:40 AM, Jason Rodriguez wrote:
Hello, I have a graphics-related question:

I was wondering if anyone knows of a way to create a bar chart that is colored 
with a three-part gradient that changes at fixed y-values. Each bar needs to 
fade green-to-yellow at Y=.10 and from yellow-to-red at Y=.20. Is there an 
option in a package somewhere that offers an easy way to do this?

Attached is a chart I macgyvered together in Excel using a combination of a 
simple bar chart, fit line, and some drawing tools. I want to avoid doing it 
this way in the future by finding a way to replicate it in R.

Any ideas?

Hi Jason,
When I first read your message, I immediately thought of using gradient.rect (plotrix). With a bit of recoding, the barp function (also in plotrix) could use gradient.rect instead of rect. The trick would be to create a vector of colors that would fill the tallest bar and pass that as "col". Only the colors that are necessary to fill each bar will actually be displayed. To get such a vector, stick together sequences of constant colors plus sequences from the color.scale function (or similar) for the fades. Once you have created the vector of desired colors, you can just pass that. I think this would be a custom function you could program unless lots of people leap up in joy at the thought of such a bar plot.

Jim

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to