R 2.15.2
OS X
Colleagues,
I often use rainbow to select colors. I encountered a surprise with
rainbow(11). It yielded three greens (in positions 4-6). The first two of
these are quite similar. The man pages suggest that this might be the case:
equispaced hues in RGB space tend to cluster at the red, green and blue
primaries
The following code illustrates the problem -- the colors labeled 4 and 5 are
quite similar.
plot(1, type="n", xlim=c(1, 10), ylim=c(0, 1), axes=F, xlab="", ylab="")
for (which in 3:7)
{
rect(which - 1, 0, which, 1, border=NA, col=rainbow(11)[which])
text(which - 0.5, 0.8, which)
text(which - 0.5, 0.2, rainbow(11)[which], srt=90)
}
In this case, I overcame the problem by replacing one element on the rainbow
vector with a different green.
Is there some better approach to this by which I could automate the entire
process but prevent this similarity of colors?
Dennis
Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-866-PLessThan (1-866-753-7784)
www.PLessThan.com
______________________________________________
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.
