discrete_scale.Rd

% Generated by roxygen2 (4.1.0): do not edit by hand
% Please edit documentation in R/scale-.r
\name{discrete_scale}
\alias{discrete_scale}
\title{Discrete scale constructor.}
\usage{
discrete_scale(aesthetics, scale_name, palette, name = NULL,
  breaks = waiver(), labels = waiver(), legend = NULL, limits = NULL,
  expand = waiver(), na.value = NA, drop = TRUE, guide = "legend")
}
\arguments{
\item{aesthetics}{the names of the aesthetics that this scale works with}

\item{scale_name}{the name of the scale}

\item{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}

\item{name}{the name of the scale - used as the axis label or the legend
title}

\item{breaks}{control the breaks in the guide.  There are four possible
types of input:
\itemize{
  \item \code{NULL}: don't display any breaks
  \item a character vector giving the breaks as they should appear on the
   axis or in the legend.
  \item \code{waiver()} to use the default break computation.
  \item 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.}

\item{labels}{\code{NULL} for no labels, \code{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.}

\item{legend}{deprecated.  Use \code{guide} instead.}

\item{limits}{A character vector specifying the data range for the scale.
and the default order of their display in guides.}

\item{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.}

\item{na.value}{how should missing values be displayed?}

\item{drop}{drop unused factor levels from the scale (\code{TRUE} or
\code{FALSE})}

\item{guide}{the name of, or actual function, used to create the
guide.}
}
\description{
Discrete scale constructor.
}
\keyword{internal}