geom_boundary_cn {ggmapcn} | R Documentation |
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()