visColoralpha {supraHex} | R Documentation

## Function to add transparent (alpha) into colors

### Description

`visColoralpha` is supposed to add transparent (alpha) into colors.

### Usage

    visColoralpha(col, alpha)

### Arguments

`col` | input colors. It can be vector of R color specifications, such as a color name (as listed by 'colors()), a hexadecimal string of the form "#rrggbb" or "#rrggbbaa"
`alpha` | numeric vector of values in the range [0, 1] for alpha transparency channel (0 means transparent and 1 means opaque)

### Value

a vector of colors (after transparent being added)

### Note

none

### See Also

`visColormap`

### Examples

    # 1) define "blue-white-red" colormap
    palette.name <- visColormap(colormap="bwr")

    # 2) use the return function "palette.name" to generate 10 colors spanning "bwr"
    col <- palette.name(10)

    # 3) add transparent (alpha=0.5)
    cols <- visColoralpha(col, alpha=0.5)

[Package supraHex version 1.20.0 Index]