col2grey: Convert colors to grey/grayscale

Description

Convert colors to grey/grayscale so that you can see how your plot will look after photocopying or printing to a non-color printer.

Usage

col2grey(cols)
col2gray(cols)

Arguments

cols

Colors to convert.

Value

A vector of colors (greys) corresponding to the input colors.

Details

converts colors to greyscale using the formula grey=0.3*red + 0.59*green + 0.11*blue. This allows you to see how your color plot will approximately look when printed on a non-color printer or photocopied.

Examples

Run this code

# NOT RUN {
par(mfcol=c(2,2))
tmp <- 1:3
names(tmp) <- c('red','green','blue')

barplot( tmp, col=c('red','green','blue') )
barplot( tmp, col=col2gray( c('red','green','blue') ) )

barplot( tmp, col=c('red','#008100','#3636ff') )
barplot( tmp, col=col2grey( c('red','#008100','#3636ff') ) )
# }