R/scale_edge_size.R

In YTLogos/ggraph: An Implementation of Grammar of Graphics for Graphs and Networks

#' Edge size scales
#'
#' This set of scales defines new size scales for edge geoms equivalent to the
#' ones already defined by ggplot2. See \code{\link[ggplot2]{scale_size}} for
#' more information. The different geoms will know whether to use edge scales or
#' the standard scales so it is not necessary to write \code{edge_size} in
#' the call to the geom - just use \code{size}.
#'
#' @note In ggplot2 size conflates both line width and point size into one
#' scale. In ggraph there is also a width scale (\code{\link{scale_edge_width}})
#' that is used for linewidth. As edges are often represented by lines the width
#' scale is the most common.
#'
#' @return A ggproto object inheriting from \code{Scale}
#'
#' @family scale_edge_*
#'
#' @name scale_edge_size
#' @rdname scale_edge_size
#'
NULL

#' @rdname scale_edge_size
#'
#' @inheritParams ggplot2::scale_size_continuous
#'
#' @importFrom scales area_pal
#' @export
scale_edge_size_continuous <- function(..., range = c(1, 6)) {
    continuous_scale("edge_size", "area", area_pal(range), ...)
}
#' @rdname scale_edge_size
#'
#' @inheritParams ggplot2::scale_radius
#'
#' @importFrom scales rescale_pal
#' @export
scale_edge_radius <- function(..., range = c(1, 6)) {
    continuous_scale("edge_size", "radius", rescale_pal(range), ...)
}
#' @rdname scale_edge_size
#'
#' @export
scale_edge_size <- scale_edge_size_continuous
#' @rdname scale_edge_size
#'
#' @inheritParams ggplot2::scale_size_discrete
#'
#' @importFrom scales rescale_pal
#' @export
scale_edge_size_discrete <- function(..., range = c(2, 6)) {
    discrete_scale("edge_size", "size_d", function(n) {
        area <- seq(range[1] ^ 2, range[2] ^ 2, length.out = n)
        sqrt(area)
    }, ...)
}
#' @rdname scale_edge_size
#'
#'
#' @inheritParams ggplot2::scale_size_area
#'
#' @importFrom scales abs_area rescale_max
#' @export
scale_edge_size_area <- function(..., max_size = 6) {
    continuous_scale("edge_size", "area",
                     palette = abs_area(max_size),
                     rescaler = rescale_max, ...)
}
#' @rdname scale_edge_size
#'
#' @inheritParams ggplot2::scale_size_manual
#'
#' @export
scale_edge_size_manual <- function(..., values) {
    manual_scale("edge_size", values, ...)
}
#' @rdname scale_edge_size
#'
#' @inheritParams ggplot2::scale_size_identity
#'
#' @importFrom scales identity_pal
#' @export
scale_edge_size_identity <- function(..., guide = "none") {
    sc <- discrete_scale("edge_size", "identity", identity_pal(), ...,
                         guide = guide, super = ScaleDiscreteIdentity)
    sc
}