rsaga.union.polygons {RSAGA}

Spatial union of two polygon layers

Description

The function rsaga.union.polygons uses SAGA function "Union" to calculate the geometric union of two polygon layers. This corresponds to the intersection and the symmetrical difference of the two layers.

Usage

rsaga.union.polygons(
  layer_a = NULL,
  layer_b = NULL,
  result = NULL,
  split = FALSE,
  load = NULL,
  env = rsaga.env()
)

Arguments

layer_a

A character string representing the path to a polygon shapefile.

layer_b

A character string representing the path to a polygon shapefile with which to union layer_a.

result

character, path indicating where to store the output shapefile.

split

If TRUE, multipart polygons become separated polygons (default: FALSE).

load

Deprecated, will be removed in a future release. Ignored if FALSE, and causes an error if TRUE (default: NULL)

env

RSAGA geoprocessing environment created by rsaga.env(), required because module(s) depend(s) on SAGA version.

Details

Function gUnion() in rgeos package can also be used for joining intersecting polygon geometries. However, rsaga.union.polygons() will be usually much faster, especially when joining thousands of polygons.

Value

The function saves the output shapefile to the path indicated in function argument result.

Author(s)

Jannes Muenchow and Alexander Brenning (R interface), Olaf Conrad and Angus Johnson (SAGA modules)