Plot Maps

The function takes a list polygons and draws the corresponding map. Different colors for each polygon can be used.

plotmap(map, x = NA, id = NULL, select = NULL,
  legend = TRUE, names = FALSE, values = FALSE, ...)

Arguments

map: The map to be plotted, usually an object that inherits from SpatialPolygons, but may also be a list of polygons, i.e., each list entry is a matrix with x- and y-coordinates.
x: A vector, data.frame or matrix. In the latter case x should have two columns, one column that is the region identifier and one that contains the values to be plotted. In case x is a data.frame, the function searches for "character" or "factor" columns for the region identifier. If x is a matrix, the second column of x is supposed to be the region identifier. If x = NA and map is an object of class "SpatialPolygonsDataFrame" only the polygons will be plotted without using the data.
id: If argument x is a vector, argument id should contain the region identifier vector.
select: Select the column of the data in x which should be used for plotting, may be an integer or character with the corresponding column name.
legend: Should a color legend be added to the plot, see also function colorlegend.
names: If set to TRUE the name for each polygon will also be plotted at the centroids of the corresponding polygons.
values: If set to TRUE the corresponding values for each polygon will also be plotted at the centroids of the polygons.
...: Arguments to be passed to colorlegend and others, e.g. change the border of the polygons and density (mdensity for missing regions in id), see polygon.

Examples

## Example from mgcv ?mrf.
## Load Columbus Ohio crime data (see ?columbus for details and credits).
data("columb", package = "mgcv")
data("columb.polys", package = "mgcv")

## Plot the map.
plotmap(columb.polys)


## Plot aggregated data.
a <- with(columb, aggregate(crime,
  by = list("district" = district), FUN = mean))

plotmap(columb.polys, x = a$x, id = a$district)

plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft")
plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft", side.legend = 2)

plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft", side.legend = 2, side.ticks = 2)

plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft", side.legend = 2, side.ticks = 2,
  col = heat_hcl, swap = TRUE)
plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft", side.legend = 2, side.ticks = 2,
  col = heat_hcl, swap = TRUE, range = c(10, 50))

plotmap(columb.polys, x = a$x, id = a$district,
  pos = "topleft", side.legend = 2, side.ticks = 2,
  col = heat_hcl(5), swap = TRUE, range = c(10, 50),
  lrange = c(0, 60))

Arguments

See also

Examples