Plot boundary edges or segmented boundary lines

Plots boundary edges as colored LINESTRING or POLYGON outlines using ggplot2. This function is especially useful for visualizing specific edges extracted from a polygon using splitBoundaryPolyByAnchor().

Usage

plotEdge(
  boundary_poly = NULL,
  linewidth_boundary = 1,
  theme_ggplot = theme_spneigh(),
  ...
)

Arguments

boundary_poly

An sf object containing POLYGON or LINESTRING geometries and a region_id column.

linewidth_boundary

Numeric value specifying the line width of the edge. Default is 1.

theme_ggplot

A ggplot2 theme object. Default is theme_spneigh().

...

Additional arguments passed to ggplot2::geom_sf().

Value

A ggplot object displaying the edge outlines colored by region_id.

Examples

coords <- readRDS(system.file("extdata", "MouseBrainCoords.rds",
    package = "SpNeigh"
))

# Build boundary polygon and plot its outline
boundary_points <- getBoundary(
    data = coords, one_cluster = 2,
    eps = 120, minPts = 10
)
boundary_polys <- buildBoundaryPoly(boundary_points)
plotEdge(boundary_poly = boundary_polys)


# Split a polygon into edge segments and plot
boundary_edges <- splitBoundaryPolyByAnchor(boundary_polys[1, ])
plotEdge(boundary_poly = boundary_edges)