CSHShydRology (version 1.4.2)

ch_col_transparent: Add Transparency to plot colours

Description

Adds transparency to a colour based on an integer between 0 and 255, with 0 being fully transparent and 255 being opaque. Based on function rvn_col_transparent in package RavenR.

Usage

ch_col_transparent(colour, trans)

Value

res

returned updated colour code with transparency

Arguments

colour

colour that is to be made transparent, or an array of colours

trans

an integer (or array of integers) describing the degree of transparency, 0 to 255. Must be the same length as colour. Values < 10 (very transparent), values > 200 (solid colour).

Author

Rob Chlumsky; Paul Whitfield

See Also

See original code on post in Stack Overflow plot points transparent in R

Examples

 # plot randomly distributed data
plot(rnorm(20), col='black')

# create a transparent blue colour for plotting
mycol <- ch_col_transparent('blue', 100)

# plot more random points in transparent blue colour
points(rnorm(20),col = mycol)

 # plot randomly distributed data
plot(rnorm(20), col = 'blue')

# create two transparent colour for plotting
mycol <- ch_col_transparent(c('green',"red"), c(100, 200))

# plot more random points in transparent colours
points(rnorm(20), col = mycol[2])