discrete_scale {ggplot2} | R Documentation

## Discrete scale constructor.

### Description

Discrete scale constructor.

### Usage

    discrete_scale(aesthetics, scale_name, palette, name = waiver(),
      breaks = waiver(), labels = waiver(), limits = NULL,
      expand = waiver(), na.value = NA, drop = TRUE, guide = "legend")

### Arguments

`aesthetics` | the names of the aesthetics that this scale works with
`scale_name` | the name of the scale
`palette` | a palette function that when called with a single integer argument (the number of levels in the scale) returns the values that they should take
`name` | the name of the scale - used as the axis label or the legend title

`breaks`

control the breaks in the guide. There are four possible types of input:

- `NULL`: don't display any breaks

- a character vector giving the breaks as they should appear on the axis or in the legend.

- `waiver()` to use the default break computation.

- a function, that when called with a single argument, a character vector giving the limits of the scale, returns a character vector specifying which breaks to display.

This parameter does not affect in any way how the data is scaled - it only affects the appearance of the legend.

`labels` | `NULL` for no labels, `waiver()` for default labels (labels the same as breaks), a character vector the same length as breaks, or a named character vector whose names are used to match replacement the labels for matching breaks.
`limits` | A character vector specifying the data range for the scale. and the default order of their display in guides.
`expand` | a numeric vector of length two, giving a multiplicative and additive constant used to expand the range of the scales so that there is a small gap between the data and the axes. The defaults are (0,0.6) for discrete scales and (0.05,0) for continuous scales.
`na.value` | how should missing values be displayed?
`drop` | Should unused factor levels be omitted from the scale? The default, `TRUE`, uses the levels that appear in the data; `FALSE` uses all the levels in the factor.
`guide` | the name of, or actual function, used to create the guide. See `guides` for more info.

[Package ggplot2 version 2.1.0 Index]