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convert HCL to R color

Source: R/jamba-colors.r
hcl2col.Rd

Convert an HCL color matrix to vector of R hex colors

Usage

hcl2col(
  x = NULL,
  H = NULL,
  C = NULL,
  L = NULL,
  ceiling = 255,
  maxColorValue = 255,
  alpha = NULL,
  fixup = TRUE,
  model = getOption("jam.model", c("hcl", "polarLUV", "polarLAB")),
  verbose = FALSE,
  ...
)

Arguments

x

matrix of colors, with rownames "H", "C", "L", or if not supplied it looks for vectors H, C, and L accordingly. It can alternatively be supplied as an object of class polarLUV.

H, C, L

numeric vectors supplied as an alternative to x, with ranges 0 to 360, 0 to 100, and 0 to 100, respectively.

ceiling

numeric value indicating the maximum values allowed for R, G, and B after conversion by colorspace::as(x, "RGB"). This ceiling is applied after the maxColorValue is used to scale numeric values, and is intended to correct for the occurrence of values above 255, which would be outside the typical color gamut allowed for RGB colors used in R. In general, this value should not be modified.

maxColorValue

numeric value indicating the maximum RGB values, typically scaling values to a range of 0 to 255, from the default returned range of 0 to 1. In general, this value should not be modified.

alpha

optional vector of alpha values. If not supplied, and if x is supplied as a matrix with rowname "alpha", then values will be used from x["alpha",].

fixup

boolean indicating whether to use colorspace::hex(...,fixup=TRUE) for conversion to R hex colors, which is not recommended since this conversion applies some unknown non-linear transformation for colors outside the color gamut. It is here is an option for comparison, and if specifically needed.

model

character string indicating the color model to use:

  • hcl (default) uses farver

  • polarLUV uses colorspace polarLUV

  • polarLAB uses `colorspace polarLAB

verbose

logical whether to print verbose output.

...

other arguments are ignored.

Value

vector of R colors, or where the input was NA, then NA values are returned in the same order.

Details

This function takes an HCL matrix,and converts to an R color using the colorspace package colorspace::polarLUV() and colorspace::hex().

When model="hcl" this function uses farver::encode_colour() and bypasses colorspace. In future the colorspace dependency will likely be removed in favor of using farver. In any event, model="hcl" is equivalent to using model="polarLUV" and fixup=TRUE, except that it should be much faster.

See also

Other jam color functions: alpha2col(), applyCLrange(), col2alpha(), col2hcl(), col2hsl(), col2hsv(), color2gradient(), fixYellow(), fixYellowHue(), getColorRamp(), hsl2col(), hsv2col(), isColor(), kable_coloring(), makeColorDarker(), rainbow2(), rgb2col(), setCLranges(), setTextContrastColor(), showColors(), unalpha(), warpRamp()

Examples

# Prepare a basic HCL matrix
hclM <- col2hcl(c(red="red",
   blue="blue",
   yellow="yellow",
   orange="#FFAA0066"));
hclM;
#>             red      blue    yellow    orange
#> H      12.17440 265.87459  85.86596  46.97366
#> C     179.04898 130.67920 107.07044 103.64939
#> L      53.24079  32.29701  97.13927  76.07836
#> alpha   1.00000   1.00000   1.00000   0.40000

# Now convert back to R hex colors
colorV <- hcl2col(hclM);
colorV;
#>       red      blue    yellow    orange 
#> "#FF0000" "#0000FF" "#FFFF00" "#FFAA00" 

showColors(colorV);