Display how the alpha transparency for rgb() varies.
testAlpha(alpha=seq(0,1,len=25), fg="blue", bg="yellow",
border="black", grid=FALSE, ...)Invisibly returns the compound RGB matrix for fg, alpha,
bg, and border.
numeric -- vector of alpha transparency values values from 0 to 1.
character -- foreground colour of the top shape that varies in transparency.
character -- background colour (remains constant) of the underlying shape.
character -- border colour (which also changes in transparency) of the foreground polygon.
logical -- if TRUE, lay a grey grid on the background colour.
dots -- additional graphical arguments to send to the the ploting functions.
Jon T. Schnute, Research Scientist Emeritus
Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo BC
Maintainer: Rowan Haigh, Program Head -- Offshore Rockfish
Pacific Biological Station (PBS), Fisheries & Oceans Canada (DFO), Nanaimo BC
locus opus: Offsite, Vancouver BC
Last modified Rd: 2023-10-18
In package PBSmodelling:
testCol,
testLty,
testLwd
In package PBStools:
testPch