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@markheckmann
Last active March 1, 2018 21:16
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Color wheels using colorspace::hcl by luminance
library(colorspace)
polar2cart <- function(r, theta) # polar to cartesian coords
{
rad <- theta * pi /180
cbind(x = r*cos(rad),
y = r*sin(rad))
}
h <- seq(0, 360, len=150) # hue values
c <- seq(0, 100, len=100) # chroma
p <- expand.grid(h=h,c=c)
xy <- polar2cart(p$c, p$h)
color_wheel <- function(l=50)
{
col <- hcl(p$h, p$c, l)
plot(xy, pch=16, col=col, asp=1, axes=F,
main=paste("luminance:", round(l)),
xlab="", ylab="")
}
par(mfrow=c(2,2))
for (l in seq(0, 100, len=4))
color_wheel(l)
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