def geos_linestring_from_py(ob, update_geom=None, update_ndim=0):
# If a LineString is passed in, clone it and return
# If a LinearRing is passed in, clone the coord seq and return a
# LineString.
#
# NB: access to coordinates using the array protocol has been moved
# entirely to the speedups module.
if isinstance(ob, LineString):
if type(ob) == LineString:
return geos_geom_from_py(ob)
else:
return geos_geom_from_py(ob, lgeos.GEOSGeom_createLineString)
try:
m = len(ob)
except TypeError: # Iterators, e.g. Python 3 zip
ob = list(ob)
m = len(ob)
if m == 0:
return None
def _coords(o):
if isinstance(o, Point):
return o.coords[0]
else:
return o
try:
n = len(_coords(ob[0]))
except TypeError:
raise ValueError("Input %s is the wrong shape for a LineString" %
str(ob))
assert n == 2 or n == 3
# Create a coordinate sequence
if update_geom is not None:
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(m, n)
# add to coordinate sequence
for i in range(m):
coords = _coords(ob[i])
# Because of a bug in the GEOS C API,
# always set X before Y
lgeos.GEOSCoordSeq_setX(cs, i, coords[0])
lgeos.GEOSCoordSeq_setY(cs, i, coords[1])
if n == 3:
try:
lgeos.GEOSCoordSeq_setZ(cs, i, coords[2])
except IndexError:
raise ValueError("Inconsistent coordinate dimensionality")
if update_geom is not None:
return None
else:
return lgeos.GEOSGeom_createLineString(cs), n
def geos_linestring_from_py(ob, update_geom=None, update_ndim=0):
# 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']) == 2
m = array['shape'][0]
if m < 2:
raise ValueError(
"LineStrings must have at least 2 coordinate tuples")
try:
n = array['shape'][1]
except IndexError:
raise ValueError("Input %s is the wrong shape for a LineString" %
str(ob))
assert n == 2 or n == 3
# Make pointer to the coordinate array
if isinstance(array['data'], tuple):
# numpy tuple (addr, read-only)
cp = cast(array['data'][0], POINTER(c_double))
else:
cp = array['data']
# Create a coordinate sequence
if update_geom is not None:
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(m, n)
# add to coordinate sequence
for i in range(m):
dx = c_double(cp[n * i])
dy = c_double(cp[n * i + 1])
dz = None
if n == 3:
try:
dz = c_double(cp[n * i + 2])
except IndexError:
raise ValueError("Inconsistent coordinate dimensionality")
# Because of a bug in the GEOS C API,
# always set X before Y
lgeos.GEOSCoordSeq_setX(cs, i, dx)
lgeos.GEOSCoordSeq_setY(cs, i, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, i, dz)
except AttributeError:
# Fall back on list
try:
m = len(ob)
except TypeError: # Iterators, e.g. Python 3 zip
ob = list(ob)
m = len(ob)
if m < 2:
raise ValueError(
"LineStrings must have at least 2 coordinate tuples")
def _coords(o):
if isinstance(o, Point):
return o.coords[0]
else:
return o
try:
n = len(_coords(ob[0]))
except TypeError:
raise ValueError("Input %s is the wrong shape for a LineString" %
str(ob))
assert n == 2 or n == 3
# Create a coordinate sequence
if update_geom is not None:
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(m, n)
# add to coordinate sequence
for i in range(m):
coords = _coords(ob[i])
# Because of a bug in the GEOS C API,
# always set X before Y
lgeos.GEOSCoordSeq_setX(cs, i, coords[0])
lgeos.GEOSCoordSeq_setY(cs, i, coords[1])
if n == 3:
try:
lgeos.GEOSCoordSeq_setZ(cs, i, coords[2])
except IndexError:
raise ValueError("Inconsistent coordinate dimensionality")
if update_geom is not None:
return None
else:
return lgeos.GEOSGeom_createLineString(cs), n
def geos_linestring_from_py(ob, update_geom=None, update_ndim=0):
try:
# From array protocol
array = ob.__array_interface__
assert len(array['shape']) == 2
m = array['shape'][0]
if m < 2:
raise ValueError(
"LineStrings must have at least 2 coordinate tuples")
try:
n = array['shape'][1]
except IndexError:
raise ValueError(
"Input %s is the wrong shape for a LineString" % str(ob))
assert n == 2 or n == 3
# Make pointer to the coordinate array
try:
cp = cast(array['data'][0], POINTER(c_double))
except ArgumentError:
cp = array['data']
# Create a coordinate sequence
if update_geom is not None:
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(m, n)
# add to coordinate sequence
for i in xrange(m):
dx = c_double(cp[n*i])
dy = c_double(cp[n*i+1])
dz = None
if n == 3:
try:
dz = c_double(cp[n*i+2])
except IndexError:
raise ValueError("Inconsistent coordinate dimensionality")
# Because of a bug in the GEOS C API,
# always set X before Y
lgeos.GEOSCoordSeq_setX(cs, i, dx)
lgeos.GEOSCoordSeq_setY(cs, i, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, i, dz)
except AttributeError:
# Fall back on list
m = len(ob)
if m < 2:
raise ValueError(
"LineStrings must have at least 2 coordinate tuples")
try:
n = len(ob[0])
except TypeError:
raise ValueError(
"Input %s is the wrong shape for a LineString" % str(ob))
assert n == 2 or n == 3
# Create a coordinate sequence
if update_geom is not None:
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(m, n)
# add to coordinate sequence
for i in xrange(m):
coords = ob[i]
dx = c_double(coords[0])
dy = c_double(coords[1])
dz = None
if n == 3:
try:
dz = c_double(coords[2])
except IndexError:
raise ValueError("Inconsistent coordinate dimensionality")
# Because of a bug in the GEOS C API,
# always set X before Y
lgeos.GEOSCoordSeq_setX(cs, i, dx)
lgeos.GEOSCoordSeq_setY(cs, i, dy)
if n == 3:
lgeos.GEOSCoordSeq_setZ(cs, i, dz)
if update_geom is not None:
return None
else:
return lgeos.GEOSGeom_createLineString(cs), n
