murdoch@stats.uwo.ca writes:
> Ross posted this code:
>
> persp(x, y, z, col = cm.colors(10)[floor(9 * hgt + 1)], theta = 35)
>
> I hadn't seen the cm.colors function before; it's very nice! I
wanted
> to modify it a bit to allow the start and end colors as well as the
> max saturation to be specified, and I think I may have turned up a bug
> in the hsv() function. Here's the evidence of the bug:
>
> Look at the results of these two calls to hsv:
>
> > hsv(h=0.833333333333333,s=0.5,v=1)
> [1] "#FF8080"
> > hsv(h=0.8333333333333333,s=0.5,v=1)
> [1] "#FF80FF"
>
> I think the 3 color components are listed as hex values in Blue,
> Green, Red order here. The two calls have nearly identical parameters
> (differing in hue only in the 16th decimal place), but the red
> component is twice as strong in the second one.
Yes, this is a bug. It is also visible by viewing (h,hsv(h)) for
values of h close to 5/6. There appears to be a small window from
about 0.8333317 to 0.8333333 where the 3rd component is 00 instead of
FF. (The order of the components are Red, Green, Blue though....)
--
O__ ---- Peter Dalgaard Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907
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