[R] Drawing a colour wheel - bug in hcl?
h.wickham at gmail.com
Mon Jul 7 23:54:35 CEST 2008
> If you replace this by
> hcl$colour <- hcl(hcl$h, hcl$c, hcl$l, fixup = FALSE)
>> with(hcl, plot(x, y, col=colour, pch=20))
> Then, the resulting "wheel" has three overlapping "holes" corresponding to
> the colors previously fixed.
Oops, thanks for pointing that out.
> Also, as hue/chroma correspond to polar coordinates in the UV plane of
> CIELUV, it makes more sense to plot wheels in the hue/chroma plane for fixed
> luminance. To draw a hue/luminance plane for fixed chroma is harder to
> interpret geometrically.
Oooh, I guess if I'd thought about that for a couple of seconds I
would have a realised that! What are good values to use for luminance
and chroma in that case? I can't seem to find a slice which gives me
a decently wheel-like slice? Or should I just use fixup = TRUE, or
accept that true colour wheels displayed on rgb monitors don't look
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