scale_gradientn {ggplot2}R Documentation

scale_gradientn

Description

Smooth gradient between n colours

Usage

scale_colour_gradientn(name=NULL, colours, values=NULL, rescale=TRUE, space="rgb", ...)
scale_fill_gradientn(name=NULL, colours, values=NULL, rescale=TRUE, space="rgb", ...)

Arguments

name name of scale to appear in legend or on axis. Maybe be an expression: see ?plotmath
colours NULL
values NULL
rescale NULL
space colour space to interpolate through, rgb or Lab, see ?colorRamp for details
... other arguments

Details

This page describes scale_gradientn, see layer and qplot for how to create a complete plot from individual components.

Value

A layer

Author(s)

Hadley Wickham, http://had.co.nz/

See Also

Examples

## Not run: 
# scale_colour_gradient make it easy to use existing colour palettes

dsub <- subset(diamonds, x > 5 & x < 6 & y > 5 & y < 6)
dsub$diff <- with(dsub, sqrt(abs(x-y))* sign(x-y))
(d <- qplot(x, y, data=dsub, colour=diff))

d + scale_colour_gradientn(colour = rainbow(7))
breaks <- c(-0.5, 0, 0.5)
d + scale_colour_gradientn(colour = rainbow(7), 
  breaks = breaks, labels = format(breaks))

d + scale_colour_gradientn(colour = topo.colors(10))
d + scale_colour_gradientn(colour = terrain.colors(10))

# You can force them to be symmetric by supplying a vector of 
# values, and turning rescaling off
max_val <- max(abs(dsub$diff))
values <- seq(-max_val, max_val, length = 11)

d + scale_colour_gradientn(colours = topo.colors(10), 
  values = values, rescale = FALSE)
d + scale_colour_gradientn(colours = terrain.colors(10), 
  values = values, rescale = FALSE)

## End(Not run)

[Package ggplot2 version 0.8.5 Index]