def geos_point_from_py(ob, update_geom=None, update_ndim=0):
"""Create a GEOS geom from an object that is a Point, a coordinate sequence
or that provides the array interface.
Returns the GEOS geometry and the number of its dimensions.
"""
if isinstance(ob, Point):
return geos_geom_from_py(ob)
# Accept either (x, y) or [(x, y)]
if not hasattr(ob, '__getitem__'): # Iterators, e.g. Python 3 zip
ob = list(ob)
if isinstance(ob[0], tuple):
coords = ob[0]
else:
coords = ob
n = len(coords)
dx = c_double(coords[0])
dy = c_double(coords[1])
dz = None
if n == 3:
dz = c_double(coords[2])
if update_geom:
cs = lgeos.GEOSGeom_getCoordSeq(update_geom)
if n != update_ndim:
raise ValueError(
"Wrong coordinate dimensions; this geometry has dimensions: "
"%d" % update_ndim)
else:
cs = lgeos.GEOSCoordSeq_create(1, n)
# Because of a bug in the GEOS C API, always set X before Y
lgeos.GEOSCoordSeq_setX(cs, 0, dx)
lgeos.GEOSCoordSeq_setY(cs, 0, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, 0, dz)
if update_geom:
return None
else:
return lgeos.GEOSGeom_createPoint(cs), n
def geos_point_from_py(ob, update_geom=None, update_ndim=0):
"""Create a GEOS geom from an object that is a Point, a coordinate sequence
or that provides the array interface.
Returns the GEOS geometry and the number of its dimensions.
"""
if isinstance(ob, Point):
return geos_geom_from_py(ob)
# If numpy is present, we use numpy.require to ensure that we have a
# C-continguous array that owns its data. View data will be copied.
ob = required(ob)
try:
# From array protocol
array = ob.__array_interface__
assert len(array['shape']) == 1
n = array['shape'][0]
assert n == 2 or n == 3
dz = None
da = array['data']
if isinstance(da, tuple):
cdata = da[0]
# If we had numpy, we would do
# from numpy.ctypeslib import as_ctypes
# cp = as_ctypes(ob) - check that code?
cp = cast(cdata, POINTER(c_double))
dx = c_double(cp[0])
dy = c_double(cp[1])
if n == 3:
dz = c_double(cp[2])
else:
dx, dy = da[0:2]
if n == 3:
dz = da[2]
except AttributeError:
# Fall back on the case of Python sequence data
# Accept either (x, y) or [(x, y)]
if not hasattr(ob, '__getitem__'): # Iterators, e.g. Python 3 zip
ob = list(ob)
if isinstance(ob[0], tuple):
coords = ob[0]
else:
coords = ob
n = len(coords)
dx = c_double(coords[0])
dy = c_double(coords[1])
dz = None
if n == 3:
dz = c_double(coords[2])
if update_geom:
cs = lgeos.GEOSGeom_getCoordSeq(update_geom)
if n != update_ndim:
raise ValueError(
"Wrong coordinate dimensions; this geometry has dimensions: "
"%d" % update_ndim)
else:
cs = lgeos.GEOSCoordSeq_create(1, n)
# Because of a bug in the GEOS C API, always set X before Y
lgeos.GEOSCoordSeq_setX(cs, 0, dx)
lgeos.GEOSCoordSeq_setY(cs, 0, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, 0, dz)
if update_geom:
return None
else:
return lgeos.GEOSGeom_createPoint(cs), n
def geos_point_from_py(ob, update_geom=None, update_ndim=0):
"""Create a GEOS geom from an object that is a coordinate sequence
or that provides the array interface.
Returns the GEOS geometry and the number of its dimensions.
"""
try:
# From array protocol
array = ob.__array_interface__
assert len(array['shape']) == 1
n = array['shape'][0]
assert n == 2 or n == 3
dz = None
da = array['data']
if type(da) == type((0,)):
cdata = da[0]
cp = cast(cdata, POINTER(c_double))
dx = c_double(cp[0])
dy = c_double(cp[1])
if n == 3:
dz = c_double(cp[2])
ndim = 3
else:
dx, dy = da[0:2]
if n == 3:
dz = da[2]
ndim = 3
except AttributeError:
# Fall back on the case of Python sequence data
# Accept either (x, y) or [(x, y)]
if type(ob[0]) == type(tuple()):
coords = ob[0]
else:
coords = ob
n = len(coords)
dx = c_double(coords[0])
dy = c_double(coords[1])
dz = None
if n == 3:
dz = c_double(coords[2])
if update_geom:
cs = lgeos.GEOSGeom_getCoordSeq(update_geom)
if n != update_ndim:
raise ValueError(
"Wrong coordinate dimensions; this geometry has dimensions: %d" \
% update_ndim)
else:
cs = lgeos.GEOSCoordSeq_create(1, n)
# Because of a bug in the GEOS C API, always set X before Y
lgeos.GEOSCoordSeq_setX(cs, 0, dx)
lgeos.GEOSCoordSeq_setY(cs, 0, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, 0, dz)
if update_geom:
return None
else:
return lgeos.GEOSGeom_createPoint(cs), n