R/plot-polar.R

In ijlyttle/colorpath: Build Color Paths

#' Polar plot
#'
#' This can be useful in identifying issues arising from color-vision
#' deficiency. You can provide a `data.frame` that has columns
#' `luminance`, `chroma`, `hue`, `hex` - or you can provide an object
#' that can be coerced into that form using [pth_data_cvd()]: a `pth_mat`,
#' `pth_palette`, or hex-code `character`.
#'
#' If you provide the `cvd` argument anything other than the simplest case,
#' you will have to add faceting. You will have to do this yourself;
#' the operative columns are `condition` and `severity`.
#'
#' @param data object coercible to `data.frame` with columns
#'   `luminance`, `chroma`, `hue`, `hex`.
#' @inheritParams pth_data_cvd
#'
#' @return Object with S3 classes `"gg"`, `"ggplot"`; i.e. a ggplot.
#' @export
#'
pth_plot_polar <- function(data, ...) {
  UseMethod("pth_plot_polar")
}

#' @rdname pth_plot_polar
#' @export
#'
pth_plot_polar.default <- function(data, ...) {
  stop(
    glue::glue("No method for class {class(data)}")
  )
}

#' @rdname pth_plot_polar
#' @export
#'
pth_plot_polar.data.frame <- function(data, ...) {
  plot_polar(data)
}

#' @rdname pth_plot_polar
#' @export
#'
pth_plot_polar.character <- function(data, cvd = pth_cvd_grid_none(),
                                     transformer = pth_to_cieluv, ...) {

  data <- pth_data_cvd(data, cvd = cvd, transformer = transformer)

  pth_plot_polar(data)
}

#' @rdname pth_plot_polar
#' @export
#'
pth_plot_polar.pth_mat <- function(data, cvd = pth_cvd_grid_none(), ...) {

  data <- pth_data_cvd(data, cvd = cvd)

  pth_plot_polar(data)
}

#' @rdname pth_plot_polar
#' @export
#'
pth_plot_polar.pth_palette <- function(data, cvd = pth_cvd_grid_none(),
                                   n_point = 11, ...) {

  data <- pth_data_cvd(data, cvd = cvd, n_point = n_point)

  pth_plot_polar(data)
}

plot_polar <- function(data = NULL) {

  plot <-
    ggplot2::ggplot(
      data = data,
      mapping = ggplot2::aes_string(x = "hue", y = "chroma", color = "hex")
    ) +
    ggplot2::geom_point() +
    ggplot2::scale_x_continuous(limits = c(0, 360), breaks = seq(0, 360, 60)) +
    ggplot2::scale_y_continuous(limits = c(0, NA)) +
    ggplot2::scale_color_identity() +
    ggplot2::coord_polar(theta = "x", start = -pi / 2, direction = -1) +
    ggplot2::theme_bw()

  plot
}