This function transforms a standard color (e.g. "red") into an
transparent RGB-color (i.e. alpha-blend<1).
Usage
Col(col, alpha = 0.2, locate = 0)
Arguments
- col
color (numeric or character)
- alpha
degree of transparency (0-1)
- locate
Choose colour (with mouse)
Value
A character vector with elements of 7 or 9 characters, # followed
by the red, blue, green and optionally alpha values in hexadecimal (after
rescaling to '0 ... 255').
Details
This only works for certain graphics devices (Cairo-X11 (x11 as of R>=2.7),
quartz, pdf, ...).
Examples
plot(runif(1000),cex=runif(1000,0,4),
col=Col(c("darkblue","orange"),0.5),pch=16)
