Geom for inla.mesh objects

This function extracts the graph of an inla.mesh object and uses geom_line to visualize the graph's edges. Alternatively, if the color argument is provided, interpolates the colors across for a set of SpatialPixels covering the mesh area and calls gg.SpatialPixelsDataFrame() to plot the interpolation. Requires the ggplot2 package.

Usage

# S3 method for inla.mesh
gg(
  data,
  color = NULL,
  alpha = NULL,
  edge.color = "grey",
  interior = TRUE,
  int.color = "blue",
  exterior = TRUE,
  ext.color = "black",
  crs = NULL,
  mask = NULL,
  nx = 500,
  ny = 500,
  ...
)

Arguments

data

An INLA::inla.mesh object.

color

A vector of scalar values to fill the mesh with colors. The length of the vector mus correspond to the number of mesh vertices. The alternative name colour is also recognised.

alpha

A vector of scalar values setting the alpha value of the colors provided.

edge.color

Color of the mesh edges.

interior

If TRUE, plot the interior boundaries of the mesh.

int.color

Color used to plot the interior boundaries.

exterior

If TRUE, plot the exterior boundaries of the mesh.

ext.color

Color used to plot the interior boundaries.

crs

A CRS object defining the coordinate system to project the mesh to before plotting.

mask

A SpatialPolygon defining the region that is plotted.

nx

Number of pixels in x direction (when plotting using the color parameter).

ny

Number of pixels in y direction (when plotting using the color parameter).

...

ignored arguments (S3 generic compatibility).

Value

geom_line return values or, if the color argument is used, the values of gg.SpatialPixelsDataFrame().

See also

Other geomes for meshes: gg.inla.mesh.1d(), gg(), gm()

Examples

# \donttest{
if (bru_safe_inla() &&
    require(ggplot2, quietly = TRUE) &&
    require(ggpolypath, quietly = TRUE)) {

  # Load Gorilla data
  data("gorillas", package = "inlabru")

  # Plot mesh using default edge colors

  ggplot() +
    gg(gorillas$mesh)

  # Don't show interior and exterior boundaries

  ggplot() +
    gg(gorillas$mesh, interior = FALSE, exterior = FALSE)

  # Change the edge colors

  ggplot() +
    gg(gorillas$mesh,
      edge.color = "green",
      int.color = "black",
      ext.color = "blue"
    )

  # Use the x-coordinate of the vertices to colorize the triangles and
  # mask the plotted area by the survey boundary, i.e. only plot the inside

  xcoord <- gorillas$mesh$loc[, 1]
  ggplot() +
    gg(gorillas$mesh, color = (xcoord - 580), mask = gorillas$boundary) +
    gg(gorillas$boundary)
}
#> Warning: PROJ support is provided by the sf and terra packages among others
#> Regions defined for each Polygons

# }