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Last data update: 2014.03.03

R: Convert Colors to Grey/Grayscale

ColToGrey

R Documentation

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

ColToGrey(col)
ColToGray(col)

Arguments

col

vector of any of the three kind of R colors, i.e., either a color name (an element of colors()), a hexadecimal string of the form "#rrggbb" or "#rrggbbaa" (see rgb), or an integer i meaning palette()[i]. Non-string values are coerced to integer.

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.

Value

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

Note

These function was previously published as Col2Grey() in the TeachingDemos package and has been integrated here without logical changes.

Author(s)

Greg Snow <greg.snow@imail.org>

Examples

par(mfcol=c(2,2))
tmp <- 1:3
names(tmp) <- c('red','green','blue')

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

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

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DescTools)
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DescTools/ColToGrey.Rd_%03d_medium.png", width=480, height=480)
> ### Name: ColToGrey
> ### Title: Convert Colors to Grey/Grayscale
> ### Aliases: ColToGrey ColToGray
> ### Keywords: color
> 
> ### ** Examples
> 
> par(mfcol=c(2,2))
> tmp <- 1:3
> names(tmp) <- c('red','green','blue')
> 
> barplot(tmp, col=c('red','green','blue'))
> barplot(tmp, col=ColToGrey(c('red','green','blue')))
> 
> barplot(tmp, col=c('red','#008100','#3636ff'))
> barplot(tmp, col=ColToGrey(c('red','#008100','#3636ff')))
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>