metR (version 0.6.0)

scale_divergent: Divergent colour scales

Description

Wrapper around ggplot's scale_colour_gradient2 with inverted defaults of high and low.

Usage

scale_colour_divergent(
  ...,
  low = scales::muted("blue"),
  mid = "white",
  high = scales::muted("red"),
  midpoint = 0,
  space = "Lab",
  na.value = "grey50",
  guide = "colourbar"
)

scale_color_divergent( ..., low = scales::muted("blue"), mid = "white", high = scales::muted("red"), midpoint = 0, space = "Lab", na.value = "grey50", guide = "colourbar" )

scale_fill_divergent( ..., low = scales::muted("blue"), mid = "white", high = scales::muted("red"), midpoint = 0, space = "Lab", na.value = "grey50", guide = "colourbar" )

Arguments

...

Arguments passed on to continuous_scale

scale_name

The name of the scale

palette

A palette function that when called with a numeric vector with values between 0 and 1 returns the corresponding values in the range the scale maps to.

name

The name of the scale. Used as the axis or legend title. If waiver(), the default, the name of the scale is taken from the first mapping used for that aesthetic. If NULL, the legend title will be omitted.

breaks

One of:

  • NULL for no breaks

  • waiver() for the default breaks computed by the transformation object

  • A numeric vector of positions

  • A function that takes the limits as input and returns breaks as output

minor_breaks

One of:

  • NULL for no minor breaks

  • waiver() for the default breaks (one minor break between each major break)

  • A numeric vector of positions

  • A function that given the limits returns a vector of minor breaks.

labels

One of:

  • NULL for no labels

  • waiver() for the default labels computed by the transformation object

  • A character vector giving labels (must be same length as breaks)

  • A function that takes the breaks as input and returns labels as output

limits

One of:

  • NULL to use the default scale range

  • A numeric vector of length two providing limits of the scale. Use NA to refer to the existing minimum or maximum

  • A function that accepts the existing (automatic) limits and returns new limits

rescaler

Used by diverging and n colour gradients (i.e. scale_colour_gradient2(), scale_colour_gradientn()). A function used to scale the input values to the range [0, 1].

oob

Function that handles limits outside of the scale limits (out of bounds). The default replaces out of bounds values with NA.

trans

Either the name of a transformation object, or the object itself. Built-in transformations include "asn", "atanh", "boxcox", "date", "exp", "hms", "identity", "log", "log10", "log1p", "log2", "logit", "modulus", "probability", "probit", "pseudo_log", "reciprocal", "reverse", "sqrt" and "time".

A transformation object bundles together a transform, its inverse, and methods for generating breaks and labels. Transformation objects are defined in the scales package, and are called name_trans, e.g. scales::boxcox_trans(). You can create your own transformation with scales::trans_new().

position

The position of the axis. "left" or "right" for vertical scales, "top" or "bottom" for horizontal scales

super

The super class to use for the constructed scale

expand

Vector of range expansion constants used to add some padding around the data, to ensure that they are placed some distance away from the axes. Use the convenience function expand_scale() to generate the values for the expand argument. The defaults are to expand the scale by 5% on each side for continuous variables, and by 0.6 units on each side for discrete variables.

low

Colours for low and high ends of the gradient.

mid

colour for mid point

high

Colours for low and high ends of the gradient.

midpoint

The midpoint (in data value) of the diverging scale. Defaults to 0.

space

colour space in which to calculate gradient. Must be "Lab" - other values are deprecated.

na.value

Colour to use for missing values

guide

Type of legend. Use "colourbar" for continuous colour bar, or "legend" for discrete colour legend.

See Also

Other ggplot2 helpers: DivideTimeseries(), MakeBreaks(), WrapCircular(), geom_arrow(), geom_contour2(), geom_contour_fill(), geom_label_contour(), geom_relief(), geom_streamline(), guide_colourstrip(), map_labels, reverselog_trans(), scale_longitude, stat_na(), stat_subset()

Examples

Run this code
# NOT RUN {
library(ggplot2)
ggplot(reshape2::melt(volcano), aes(Var1, Var2, z = value)) +
  geom_contour(aes(color = ..level..)) +
  scale_colour_divergent(midpoint = 130)

# }

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