R: Compute Maximum Chroma for Given Hue and Luminance in HCL

max_chroma {colorspace} | R Documentation

## Compute Maximum Chroma for Given Hue and Luminance in HCL

### Description

Compute approximately the maximum chroma possible for a given hue and luminance combination in the HCL color space.

### Usage

    max_chroma(h, l, floor = FALSE)

    max_chroma_table

### Arguments

`h` | hue value in the HCL color description, has to be in [0, 360].
`l` | luminance value in the HCL color description, has to be in [0, 100].
`floor` | logical. Should the chroma value be rounded down to the next lower integer?

### Details

As the possible combinations of chroma and luminance depend on hue, it is not obvious which maximum chroma can be used for a given combination of hue and luminance prior to calling `polarLUV`. To avoid having to `fixup` the color upon conversion to RGB `hex` codes, the `max_chroma` function computes (approximately) the maximum chroma possible. The computations are based on interpolations of pre-computed maxima in `max_chroma_table`, containing the maximum chroma for a given hue-luminance combination (both in integers). Hence, the result may sometimes still be very slightly larger than the actual maximum which can be avoided by taking the `floor` of the approximate value.

### Value

A numeric vector with the maximum chroma coordinates.

### See Also

`polarLUV`, `hex`

### Examples

    max_chroma(0:36 * 10, 50)
    max_chroma(120, 0:10 * 10)

[Package colorspace version 1.4-1 Index]