Geometry binary predicates operating on WKB or WKT

These functions implement tests for pairs of geometries in OGC WKB or WKT format.

Usage

g_intersects(this_geom, other_geom, quiet = FALSE)

g_disjoint(this_geom, other_geom, quiet = FALSE)

g_touches(this_geom, other_geom, quiet = FALSE)

g_contains(this_geom, other_geom, quiet = FALSE)

g_within(this_geom, other_geom, quiet = FALSE)

g_crosses(this_geom, other_geom, quiet = FALSE)

g_overlaps(this_geom, other_geom, quiet = FALSE)

g_equals(this_geom, other_geom, quiet = FALSE)

Arguments

this_geom: Either a raw vector of WKB or list of raw vectors, or a character vector containing one or more WKT strings.
other_geom: Either a raw vector of WKB or list of raw vectors, or a character vector containing one or more WKT strings. Must contain the same number of geometries as this_geom, unless this_geom contains a single geometry in which case pairwise tests will be performed for one-to-many if other_geom contains multiple geometries (i.e., "this-to-others").
quiet: Logical value, TRUE to suppress warnings. Defaults to FALSE.

Value

Logical vector with length equal to the number of input geometry pairs.

Details

These functions use the GEOS library via GDAL headers.

g_intersects() tests whether two geometries intersect.

g_disjoint() tests if this geometry and the other geometry are disjoint.

g_touches() tests if this geometry and the other geometry are touching.

g_contains() tests if this geometry contains the other geometry.

g_within() tests if this geometry is within the other geometry.

g_crosses() tests if this geometry and the other geometry are crossing.

g_overlaps() tests if this geometry and the other geometry overlap, that is, their intersection has a non-zero area (they have some but not all points in common).

g_equals() tests whether two geometries are equivalent. The GDAL documentation says: "This operation implements the SQL/MM ST_OrderingEquals() operation. The comparison is done in a structural way, that is to say that the geometry types must be identical, as well as the number and ordering of sub-geometries and vertices. Or equivalently, two geometries are considered equal by this method if their WKT/WKB representation is equal. Note: this must be distinguished from equality in a spatial way."

Note

this_geom and other_geom are assumed to be in the same coordinate reference system.

If this_geomis a single geometry and other_geom is a list or vector of multiple geometries, then this_geom will be tested against each geometry in other_geom (otherwise no recycling is done).

Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call g_is_valid() before, otherwise the result might be wrong.