def test09a_srs(self):
"Testing OGR Geometries with Spatial Reference objects."
for mp in self.geometries.multipolygons:
# Creating a geometry w/spatial reference
sr = SpatialReference('WGS84')
mpoly = OGRGeometry(mp.wkt, sr)
self.assertEqual(sr.wkt, mpoly.srs.wkt)
# Ensuring that SRS is propagated to clones.
klone = mpoly.clone()
self.assertEqual(sr.wkt, klone.srs.wkt)
# Ensuring all children geometries (polygons and their rings) all
# return the assigned spatial reference as well.
for poly in mpoly:
self.assertEqual(sr.wkt, poly.srs.wkt)
for ring in poly:
self.assertEqual(sr.wkt, ring.srs.wkt)
# Ensuring SRS propagate in topological ops.
a = OGRGeometry(self.geometries.topology_geoms[0].wkt_a, sr)
b = OGRGeometry(self.geometries.topology_geoms[0].wkt_b, sr)
diff = a.difference(b)
union = a.union(b)
self.assertEqual(sr.wkt, diff.srs.wkt)
self.assertEqual(sr.srid, union.srs.srid)
# Instantiating w/an integer SRID
mpoly = OGRGeometry(mp.wkt, 4326)
self.assertEqual(4326, mpoly.srid)
mpoly.srs = SpatialReference(4269)
self.assertEqual(4269, mpoly.srid)
self.assertEqual('NAD83', mpoly.srs.name)
# Incrementing through the multipolyogn after the spatial reference
# has been re-assigned.
for poly in mpoly:
self.assertEqual(mpoly.srs.wkt, poly.srs.wkt)
poly.srs = 32140
for ring in poly:
# Changing each ring in the polygon
self.assertEqual(32140, ring.srs.srid)
self.assertEqual('NAD83 / Texas South Central',
ring.srs.name)
ring.srs = str(SpatialReference(4326)) # back to WGS84
self.assertEqual(4326, ring.srs.srid)
# Using the `srid` property.
ring.srid = 4322
self.assertEqual('WGS 72', ring.srs.name)
self.assertEqual(4322, ring.srid)
def test09b_srs_transform(self):
"Testing transform()."
orig = OGRGeometry('POINT (-104.609 38.255)', 4326)
trans = OGRGeometry('POINT (992385.4472045 481455.4944650)', 2774)
# Using an srid, a SpatialReference object, and a CoordTransform object
# or transformations.
t1, t2, t3 = orig.clone(), orig.clone(), orig.clone()
t1.transform(trans.srid)
t2.transform(SpatialReference('EPSG:2774'))
ct = CoordTransform(SpatialReference('WGS84'), SpatialReference(2774))
t3.transform(ct)
# Testing use of the `clone` keyword.
k1 = orig.clone()
k2 = k1.transform(trans.srid, clone=True)
self.assertEqual(k1, orig)
self.assertNotEqual(k1, k2)
prec = 3
for p in (t1, t2, t3, k2):
self.assertAlmostEqual(trans.x, p.x, prec)
self.assertAlmostEqual(trans.y, p.y, prec)