geom_boundary_cn: Plot Boundaries of China

In ggmapcn: Customizable China Map Visualizations

Plot Boundaries of China

Description

Draws various types of boundaries for China. Each boundary type can be customized in terms of color, line width, and line type. This function also allows optional addition of a compass and a scale bar.

Usage

geom_boundary_cn(
  crs = "+proj=aeqd +lat_0=35 +lon_0=105 +ellps=WGS84 +units=m +no_defs",
  compass = FALSE,
  scale = FALSE,
  mainland_color = "black",
  mainland_size = 0.5,
  mainland_linetype = "solid",
  coastline_color = "blue",
  coastline_size = 0.3,
  coastline_linetype = "solid",
  ten_segment_line_color = "black",
  ten_segment_line_size = 0.5,
  ten_segment_line_linetype = "solid",
  SAR_boundary_color = "grey",
  SAR_boundary_size = 0.5,
  SAR_boundary_linetype = "dashed",
  undefined_boundary_color = "black",
  undefined_boundary_size = 0.5,
  undefined_boundary_linetype = "longdash",
  province_color = "transparent",
  province_size = 0.3,
  province_linetype = "solid",
  ...
)

Arguments

crs	Character. Coordinate reference system (CRS) for the projection. Defaults to '"+proj=aeqd +lat_0=35 +lon_0=105 +ellps=WGS84 +units=m +no_defs"'. Users can specify other CRS strings to customize the projection (e.g., '"+proj=merc"' for Mercator).
compass	Logical. Whether to display a compass (north arrow). Default is 'FALSE'. If set to 'TRUE', a default compass (north arrow) with 'ggspatial::north_arrow_fancy_orienteering()' will be added to the top-left corner. To customize the compass, use 'ggspatial::annotation_north_arrow()' directly.
scale	Logical. Whether to display a scale bar. Default is 'FALSE'. If set to 'TRUE', a default scale bar with 'ggspatial::annotation_scale()' will be added to the bottom-left corner. To customize the scale bar, use 'ggspatial::annotation_scale()' directly.
mainland_color	Character. Color for the mainland boundary. Default is '"black"'.
mainland_size	Numeric. Line width for the mainland boundary. Default is '0.5'.
mainland_linetype	Character. Line type for the mainland boundary. Default is '"solid"'.
coastline_color	Character. Color for the coastline. Default is '"blue"'.
coastline_size	Numeric. Line width for the coastline. Default is '0.3'.
coastline_linetype	Character. Line type for the coastline. Default is '"solid"'.
ten_segment_line_color	Character. Color for the ten-segment line. Default is '"black"'.
ten_segment_line_size	Numeric. Line width for the ten-segment line. Default is '0.5'.
ten_segment_line_linetype	Character. Line type for the ten-segment line. Default is '"solid"'.
SAR_boundary_color	Character. Color for the SAR boundary. Default is '"grey"'.
SAR_boundary_size	Numeric. Line width for the SAR boundary. Default is '0.5'.
SAR_boundary_linetype	Character. Line type for the SAR boundary. Default is '"dashed"'.
undefined_boundary_color	Character. Color for the undefined boundary. Default is '"black"'.
undefined_boundary_size	Numeric. Line width for the undefined boundary. Default is '0.5'.
undefined_boundary_linetype	Character. Line type for the undefined boundary. Default is '"longdash"'.
province_color	Character. Color for the provincial boundaries. Default is '"transparent"'.
province_size	Numeric. Line width for the provincial boundaries. Default is '0.3'.
province_linetype	Character. Line type for the provincial boundaries. Default is '"solid"'.
...	Additional parameters passed to 'geom_sf'.

Value

A list of ggplot2 layers representing China's multi-segment boundaries with the specified styles. Optionally includes a compass (north arrow) and a scale bar, depending on the 'compass' and 'scale' arguments.

Examples

# Plot China's boundaries with default settings
ggplot() +
  geom_boundary_cn() +
  theme_minimal()

# Plot China's boundaries with a compass and scale bar
ggplot() +
  geom_boundary_cn(compass = TRUE, scale = TRUE) +
  theme_minimal()

# For customized compass or scale bar, use ggspatial directly:
ggplot() +
  geom_boundary_cn() +
  ggspatial::annotation_north_arrow(
    location = "br", style = ggspatial::north_arrow_minimal()
  ) +
  ggspatial::annotation_scale(
    location = "tr", width_hint = 0.3
  ) +
  theme_minimal()

ggmapcn documentation built on April 12, 2025, 2:09 a.m.