Plot Offset Polygons — plot_offset

Plot the offset polygons generated by the `generate_offset_polygon` function.

Usage

plot_offset_polygon(
  offset_polygons,
  plot_original_polygon = TRUE,
  fill = NA,
  color = "dodgerblue",
  xlim = NULL,
  ylim = NULL,
  linewidth = 1,
  background = "white",
  plot_skeleton = FALSE,
  return_layers = FALSE,
  ...
)

Arguments

offset_polygons: Default `NULL`. A `rayskeleton_polygon` or `rayskeleton_polygon_list` object, generated from `generate_offset_polygon()`.
plot_original_polygon: Default `TRUE`. Whether to plot the original polygon.
fill: Default `NULL`. A color or palette function to generate the fill palette for the polygons' interiors.
color: Default `grDevices::heat.colors`. A color or palette function to generate the color palette for the offset polygons' borders.
xlim: Default `NULL`. The x-axis limits as a vector of two values (min, max). If `NULL`, it calculates the limits from the data.
ylim: Default `NULL`. The y-axis limits as a vector of two values (min, max). If `NULL`, it calculates the limits from the data.
linewidth: Default `1`. The linewidth of the polygon.
background: Default `"white"`. Background color.
plot_skeleton: Default `FALSE`. Whether to plot the straight skeleton.
return_layers: Default `FALSE`, plots the figure. If `TRUE`, this will instead return a list of the ggplot layers.
...: Additional arguments to pass to `plot_skeleton()` if `plot_skeleton = TRUE`

Value

A plot showing the offset polygons.

Examples

# Outer polygon
vertices = matrix(c(0,0, 7,0, 7,7, 0,7, 0,0), ncol = 2, byrow = TRUE)
# Holes inside the polygon
hole_1 = matrix(c(1,1, 2,1, 2,2, 1,2, 1,1), ncol = 2, byrow = TRUE)[5:1,]
hole_2 = matrix(c(5,5, 6,5, 6,6, 5,6, 5,5), ncol = 2, byrow = TRUE)[5:1,]
skeleton = skeletonize(vertices, holes = list(hole_1, hole_2))
if(run_docs_raybevel()) {
plot_skeleton(skeleton)
}


#Generate three offsets with the skeleton
if(run_docs_raybevel()) {
plot_offset_polygon(generate_offset_polygon(skeleton, c(0.25,0.75,1.5,2)), plot_skeleton = TRUE)
}


#Generate many offsets
if(run_docs_raybevel()) {
plot_offset_polygon(generate_offset_polygon(skeleton, seq(0.05,2.55,by=0.1)))
}


#Pass a palette
if(run_docs_raybevel()) {
plot_offset_polygon(generate_offset_polygon(skeleton, seq(0.05,2.55,by=0.1)),
                    color = heat.colors)
}


#Pass colors manually (colors in excess of the number of offsets are ignored)
if(run_docs_raybevel()) {
plot_offset_polygon(generate_offset_polygon(skeleton, seq(0.05,2.55,by=0.1)),
                    color = rep(c("red","red","blue","blue"),100))
}


# Skeletonize and plot an {sf} object
if(run_docs_raybevel()) {
  us_states = spData::us_states
  texas = us_states[us_states$NAME == "Texas",]
  texas_skeleton = skeletonize(texas)
  plot_offset_polygon(generate_offset_polygon(texas_skeleton, seq(0, 2.5, by = 0.1)),
                      color = heat.colors,
                      linewidth = 1)
}