| scale_colour_gradient2 {ggplot2} | R Documentation |
Diverging colour gradient
scale_colour_gradient2(..., low = muted("red"), mid = "white",
high = muted("blue"), midpoint = 0, space = "rgb",
na.value = "grey50", guide = "colourbar")
scale_fill_gradient2(..., low = muted("red"), mid = "white",
high = muted("blue"), midpoint = 0, space = "rgb",
na.value = "grey50", guide = "colourbar")
scale_color_gradient2(..., low = muted("red"), mid = "white",
high = muted("blue"), midpoint = 0, space = "rgb",
na.value = "grey50", guide = "colourbar")
... |
Other arguments passed on to |
low |
colour for low end of gradient. |
mid |
colour for mid point |
high |
colour for high end of gradient. |
midpoint |
The midpoint (in data value) of the diverging scale. Defaults to 0. |
space |
colour space in which to calculate gradient. "Lab" usually best unless gradient goes through white. |
na.value |
Colour to use for missing values |
guide |
Type of legend. Use |
Other colour scales: scale_color_brewer,
scale_color_distiller,
scale_colour_brewer,
scale_colour_distiller,
scale_fill_brewer,
scale_fill_distiller;
scale_color_continuous,
scale_color_gradient,
scale_colour_continuous,
scale_colour_gradient,
scale_fill_continuous,
scale_fill_gradient;
scale_color_discrete,
scale_color_hue,
scale_colour_discrete,
scale_colour_hue,
scale_fill_discrete,
scale_fill_hue;
scale_color_gradientn,
scale_colour_gradientn,
scale_fill_gradientn;
scale_color_grey,
scale_colour_grey,
scale_fill_grey
dsub <- subset(diamonds, x > 5 & x < 6 & y > 5 & y < 6)
dsub$diff <- with(dsub, sqrt(abs(x-y))* sign(x-y))
(d <- qplot(x, y, data=dsub, colour=diff))
d + scale_colour_gradient2()
# Change scale name
d + scale_colour_gradient2(expression(sqrt(abs(x - y))))
d + scale_colour_gradient2("Difference\nbetween\nwidth and\nheight")
# Change limits and colours
d + scale_colour_gradient2(limits=c(-0.2, 0.2))
# Using "muted" colours makes for pleasant graphics
# (and they have better perceptual properties too)
library(scales) # for muted
d + scale_colour_gradient2(low="red", high="blue")
d + scale_colour_gradient2(low=muted("red"), high=muted("blue"))
# Using the Lab colour space also improves perceptual properties
# at the price of slightly slower operation
d + scale_colour_gradient2(space="Lab")
# About 5% of males are red-green colour blind, so it's a good
# idea to avoid that combination
d + scale_colour_gradient2(high=muted("green"))
# We can also make the middle stand out
d + scale_colour_gradient2(mid=muted("green"), high="white", low="white")
# or use a non zero mid point
(d <- qplot(carat, price, data=diamonds, colour=price/carat))
d + scale_colour_gradient2(midpoint=mean(diamonds$price / diamonds$carat))
# Fill gradients work much the same way
p <- qplot(letters[1:5], 1:5, fill= c(-3, 3, 5, 2, -2), geom = "bar",
stat = "identity")
p + scale_fill_gradient2("fill")
# Note how positive and negative values of the same magnitude
# have similar intensity