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

## Usage

```
g_intersects(this_geom, other_geom)
g_disjoint(this_geom, other_geom)
g_touches(this_geom, other_geom)
g_contains(this_geom, other_geom)
g_within(this_geom, other_geom)
g_crosses(this_geom, other_geom)
g_overlaps(this_geom, other_geom)
g_equals(this_geom, other_geom)
```

## Arguments

- this_geom
Character. OGC WKT string for a simple feature geometry.

- other_geom
Character. OGC WKT string for a simple feature geometry.

## 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

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.