[R] Drawing a colour wheel - bug in hcl?
hadley wickham
h.wickham at gmail.com
Mon Jul 7 18:06:38 CEST 2008
Hi All,
I'm trying trying to draw a colour wheel (a slice of hcl space) in R.
Running the code below doesn't give me what I expect - there's some
oddly bright colours of the wrong hue around c(0, 0) and I see three
coloured circles (a small magenta, a medium sized yellow and a large
cyan). Am I doing something wrong or is there a bug in the hcl code?
(Also any suggestions for generating a more evenly spaced grid of
colours would be greatly appreciated)
Regards,
Hadley
hcl <- expand.grid(h = seq(0, 360, by = 2), c = 70, l = seq(0, 100, by
= 2), fixup=FALSE)
hcl <- transform(hcl,
angle = h * pi / 180,
radius = l / 100
)
hcl <- transform(hcl,
x = radius * sin(angle),
y = radius * cos(angle)
)
hcl$colour <- hcl(hcl$h, hcl$c, hcl$l)
with(hcl, plot(x, y, col=colour, pch=20))
--
http://had.co.nz/
More information about the R-help
mailing list