R: Read SpatialPolygons and SpatialLines objects

Spatial2map {maps} | R Documentation

## Read SpatialPolygons and SpatialLines objects

### Description

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

### Usage

    	SpatialPolygons2map(database, namefield=NULL)
    	SpatialLines2map(database, namefield=NULL)

### Arguments

`database` | A `SpatialPolygons` or `SpatialLines` 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.

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), `readShapePoly` (in the `maptools` library)

[Package maps version 3.3.0 Index]