Make Colors Transparent
Takes a vector of colors (as color names or rgb hex values) and adds a specified alpha transparency to each.
trans.colors(col, alpha = 0.5, names = NULL)
col |
A character vector of colors, either as color names or rgb hex values |
alpha |
alpha transparency value(s) to apply to each color (0 means fully transparent and 1 means opaque) |
names |
optional character vector of names for the colors |
Colors (col) and alpha need not be of the same length.
The shorter one is replicated to make them of the same length.
A vector of color values of the form "#rrggbbaa"
Michael Friendly
trans.colors(palette(), alpha=0.5)
# alpha can be vectorized
trans.colors(palette(), alpha=seq(0, 1, length=length(palette())))
# lengths need not match: shorter one is repeated as necessary
trans.colors(palette(), alpha=c(.1, .2))
trans.colors(colors()[1:20])
# single color, with various alphas
trans.colors("red", alpha=seq(0,1, length=5))
# assign names
trans.colors("red", alpha=seq(0,1, length=5), names=paste("red", 1:5, sep=""))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.