adjustcolorHSV: Adjust Colors in One or More Directions Conveniently.
In AkselA/R-ymse: Ymse (Various)

Description Usage Arguments Details Value Examples

Adjust or modify a vector of colors by "turning knobs" on one or more coordinates in (h,s,v,α) space, typically by up or down scaling them.

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adjustcolorHSV(col, alpha.f = 1, h.f = 1, s.f = 1, v.f = 1,
  offset = c(0, 0, 0, 0), transform = diag(c(h.f, s.f, v.f, alpha.f)),
  h = NULL, s = NULL, v = NULL, alpha = NULL)

`col`	vector of colors, in any format that col2rgb() accepts
`alpha.f, h.f, s.f, v.f`	factors scaling the opacity, hue, saturation and value of `col`
`offset`	a length 4 numeric vector specifying the linear offset applied to the hue, saturation, value and alpha values
`transform`	a 4x4 diagonal matrix specifying the scaling applied to the hue, saturation, value and alpha values
`h, s, v, alpha`	fixed vlues for hue, saturation, value and alpha. Overrides any corresponding scaling factor or offset

Essentially an HSV version of the RGB-based adjustcolor. One important distinction is that the h.f value wraps around to fit the [0, 1] range, rather than simply "clamping" it between 0 and 1.

A character vector the same length as col contaning color data in standard hexadeximal RGBA format.

# Halve the saturation and value of the default palette colours
plot(2:8, cex=5, lwd=4, pch=21, bg=2:8, 
  col=adjustcolorHSV(2:8, s.f=0.5, v.f=0.6))

# Offset the hue of the default palette colours by 0.5, inverting the colours
plot(2:8, cex=5, lwd=4, pch=21, bg=2:8, 
  col=adjustcolorHSV(2:8, offset=c(0.5, 0, 0, 0)))