R: Fast color interpolation

colour_ramp {scales} | R Documentation

## Fast color interpolation

### Description

Returns a function that maps the interval [0,1] to a set of colors. Interpolation is performed in the CIELAB color space. Similar to `colorRamp(space = 'Lab')`, but hundreds of times faster, and provides results in `"#RRGGBB"` (or `"#RRGGBBAA"`) character form instead of RGB color matrices.

### Usage

    colour_ramp(colors, na.color = NA, alpha = FALSE)

### Arguments

`colors` | Colors to interpolate; must be a valid argument to `col2rgb`. This can be a character vector of `"#RRGGBB"` or `"#RRGGBBAA"`, color names from `colors`, or a positive integer that indexes into `palette()`.
`na.color` | The color to map to `NA` values (for example, `"#606060"` for dark grey, or `"#00000000"` for transparent) and values outside of [0,1]. Can itself by `NA`, which will simply cause an `NA` to be inserted into the output.
`alpha` | Whether to include alpha channels in interpolation; otherwise, any alpha information will be discarded. If `TRUE` then the returned function will provide colors in `"#RRGGBBAA"` format instead of `"#RRGGBB"`.

### Value

A function that takes a numeric vector and returns a character vector of the same length with RGB or RGBA hex colors.

### See Also

colorRamp

[Package scales version 0.5.0 Index]