Module: RGeo::Feature::MultiPolygon
Overview
SFS 1.1 Description
A MultiPolygon is a MultiSurface whose elements are Polygons.
The assertions for MultiPolygons are as follows.
a) The interiors of 2 Polygons that are elements of a MultiPolygon may not intersect.
b) The boundaries of any 2 Polygons that are elements of a MultiPolygon may not “cross” and may touch at only a finite number of Points. NOTE: Crossing is prevented by assertion (a) above.
c) A MultiPolygon is defined as topologically closed.
d) A MultiPolygon may not have cut lines, spikes or punctures, a MultiPolygon is a regular closed Point set:
e) The interior of a MultiPolygon with more than 1 Polygon is not connected, the number of connected components of the interior of a MultiPolygon is equal to the number of Polygons in the MultiPolygon.
The boundary of a MultiPolygon is a set of closed Curves (LineStrings) corresponding to the boundaries of its element Polygons. Each Curve in the boundary of the MultiPolygon is in the boundary of exactly 1 element Polygon, and every Curve in the boundary of an element Polygon is in the boundary of the MultiPolygon.
NOTE: The subclass of Surface named Polyhedral Surface is a faceted Surface whose facets are Polygons. A Polyhedral Surface is not a MultiPolygon because it violates the rule for MultiPolygons that the boundaries of the element Polygons intersect only at a finite number of Points.
Notes
MultiPolygon is defined as a module and is provided primarily for the sake of documentation. Implementations need not necessarily include this module itself. Therefore, you should not depend on the kind_of? method to check type. Instead, use the provided check_type class method (or === operator) defined in the Type module.
Constant Summary
Constants included from Type
Method Summary
Methods included from Type
check_type, subtype_of?, type_name
Methods included from MultiSurface
#area, #centroid, #point_on_surface
Methods included from GeometryCollection
#[], #each, #geometry_n, #num_geometries, #size
Methods included from Geometry
#*, #+, #-, #==, #as_binary, #as_text, #boundary, #buffer, #contains?, #convex_hull, #crosses?, #difference, #dimension, #disjoint?, #distance, #envelope, #eql?, #equals?, #factory, #geometry_type, #intersection, #intersects?, #is_empty?, #is_simple?, #overlaps?, #relate, #srid, #sym_difference, #touches?, #union, #within?