togray: Convert continuous variable to grey levels

In basille/basr: Basic, but hopefully useful, functions

Description

Convert a continuous variable to the corresponding levels of grey.

Usage

togray(x, min = 0.1, max = 0.9, alpha = NULL, inverse = FALSE,
  sqrt = FALSE)

togrey(x, min = 0.1, max = 0.9, alpha = NULL, inverse = FALSE,
  sqrt = FALSE)

Arguments

x	A numeric vector.
min	The minimum grey level.
max	The maximum grey level.
alpha	The opacity.
inverse	Logical. By default, bigger is darker. If inverse = TRUE, bigger is lighter.
sqrt	Logical. Applies a square root transformation to get more progressive grey levels.

Value

A vector of colors of the same length as x.

Author(s)

From Clement Calenge, modified by Mathieu Basille [e-mail]

Examples

bla <- runif(10000)
plot(bla, col = togray(bla, 0, 1), pch = 20)
plot(bla, col = togray(bla, 0, 1, sqrt = TRUE), pch = 20)
plot(bla, col = togray(bla, 0, 1, alpha = 0.5), pch = 20)

basille/basr documentation built on May 11, 2019, 8:32 p.m.