Spatial2map {maps}R Documentation

Read sf, SpatialPolygons and SpatialLines objects

Description

These functions transform some classes provided by the packages sp and sf into a simple list that can be used by map().

Usage

	SpatialPolygons2map(database, namefield=NULL)
	SpatialLines2map(database, namefield=NULL)
        sf2map(database, namefield="name")

Arguments

database

A SpatialPolygons, SpatialLines or sf object.

namefield

The name of a data column in database to be used for naming the polygons (or lines). If it is a vector of names, these are all used and separated by a colon ':'. Not case sensitive. So if the database contains columns that only differ by case, you get a warning and namefield is not used at all.

Details

The 'map' list object only preserves co-ordinates and polygon names. All other information available in the original data is lost. For instance, plotting order for enclaves may be wrong, resulting in invisible polygons when setting fill=TRUE.

The option namefield is only taken into account if database is class Spatial[]DataFrame. namefield may be a vector of column names, e.g. to get polygons named as 'country:state'.

Value

A list with four components: x, y, names, range, similar to the return value of map(). This data can be used as a database for map(). The lines and polygons are separated by NA.

See Also

map,SpatialPolygons (in the sp library).

[Package maps version 3.4.3 Index]