col.alpha {MESS}

Add and set alpha channel for RGB color

Description

Add and set alpha channel

Usage

col.alpha(col, alpha = 1)

Arguments

col

a vector of RGB color(s)

alpha

numeric value between 0 and 1. Zero results fully transparent and 1 means full opacity

Details

This function adds and set an alpha channel to a RGB color

Author(s)

Claus Ekstrom [e-mail]

References

Ekstrom, CT (2011) The R Primer.

Examples

newcol <- col.alpha("blue", .5)