forked from 170010011/fr
1034 lines
33 KiB
Python
1034 lines
33 KiB
Python
"""Base geometry class and utilities
|
|
|
|
Note: a third, z, coordinate value may be used when constructing
|
|
geometry objects, but has no effect on geometric analysis. All
|
|
operations are performed in the x-y plane. Thus, geometries with
|
|
different z values may intersect or be equal.
|
|
"""
|
|
|
|
from binascii import a2b_hex
|
|
from ctypes import pointer, c_size_t, c_char_p, c_void_p
|
|
from itertools import islice
|
|
import logging
|
|
import math
|
|
import sys
|
|
from warnings import warn
|
|
from functools import wraps
|
|
|
|
from shapely.affinity import affine_transform
|
|
from shapely.coords import CoordinateSequence
|
|
from shapely.errors import WKBReadingError, WKTReadingError
|
|
from shapely.geos import WKBWriter, WKTWriter
|
|
from shapely.geos import lgeos
|
|
from shapely.impl import DefaultImplementation, delegated
|
|
|
|
log = logging.getLogger(__name__)
|
|
|
|
if sys.version_info[0] < 3:
|
|
range = xrange
|
|
integer_types = (int, long)
|
|
else:
|
|
integer_types = (int,)
|
|
|
|
|
|
try:
|
|
import numpy as np
|
|
integer_types = integer_types + (np.integer,)
|
|
except ImportError:
|
|
pass
|
|
|
|
|
|
GEOMETRY_TYPES = [
|
|
'Point',
|
|
'LineString',
|
|
'LinearRing',
|
|
'Polygon',
|
|
'MultiPoint',
|
|
'MultiLineString',
|
|
'MultiPolygon',
|
|
'GeometryCollection',
|
|
]
|
|
|
|
|
|
def dump_coords(geom):
|
|
"""Dump coordinates of a geometry in the same order as data packing"""
|
|
if not isinstance(geom, BaseGeometry):
|
|
raise ValueError('Must be instance of a geometry class; found ' +
|
|
geom.__class__.__name__)
|
|
elif geom.type in ('Point', 'LineString', 'LinearRing'):
|
|
return geom.coords[:]
|
|
elif geom.type == 'Polygon':
|
|
return geom.exterior.coords[:] + [i.coords[:] for i in geom.interiors]
|
|
elif geom.type.startswith('Multi') or geom.type == 'GeometryCollection':
|
|
# Recursive call
|
|
return [dump_coords(part) for part in geom]
|
|
else:
|
|
raise ValueError('Unhandled geometry type: ' + repr(geom.type))
|
|
|
|
|
|
def geometry_type_name(g):
|
|
if g is None:
|
|
raise ValueError("Null geometry has no type")
|
|
return GEOMETRY_TYPES[lgeos.GEOSGeomTypeId(g)]
|
|
|
|
|
|
def geom_factory(g, parent=None):
|
|
# Abstract geometry factory for use with topological methods below
|
|
if not g:
|
|
raise ValueError("No Shapely geometry can be created from null value")
|
|
ob = BaseGeometry()
|
|
geom_type = geometry_type_name(g)
|
|
# TODO: check cost of dynamic import by profiling
|
|
mod = __import__(
|
|
'shapely.geometry',
|
|
globals(),
|
|
locals(),
|
|
[geom_type],
|
|
)
|
|
ob.__class__ = getattr(mod, geom_type)
|
|
ob._geom = g
|
|
ob.__p__ = parent
|
|
if lgeos.methods['has_z'](g):
|
|
ob._ndim = 3
|
|
else:
|
|
ob._ndim = 2
|
|
ob._is_empty = False
|
|
return ob
|
|
|
|
|
|
def geom_from_wkt(data):
|
|
warn("`geom_from_wkt` is deprecated. Use `geos.wkt_reader.read(data)`.",
|
|
DeprecationWarning)
|
|
if sys.version_info[0] >= 3:
|
|
data = data.encode('ascii')
|
|
geom = lgeos.GEOSGeomFromWKT(c_char_p(data))
|
|
if not geom:
|
|
raise WKTReadingError(
|
|
"Could not create geometry because of errors while reading input.")
|
|
return geom_factory(geom)
|
|
|
|
|
|
def geom_to_wkt(ob):
|
|
warn("`geom_to_wkt` is deprecated. Use `geos.wkt_writer.write(ob)`.",
|
|
DeprecationWarning)
|
|
if ob is None or ob._geom is None:
|
|
raise ValueError("Null geometry supports no operations")
|
|
return lgeos.GEOSGeomToWKT(ob._geom)
|
|
|
|
|
|
def deserialize_wkb(data):
|
|
geom = lgeos.GEOSGeomFromWKB_buf(c_char_p(data), c_size_t(len(data)))
|
|
if not geom:
|
|
raise WKBReadingError(
|
|
"Could not create geometry because of errors while reading input.")
|
|
return geom
|
|
|
|
|
|
def geom_from_wkb(data):
|
|
warn("`geom_from_wkb` is deprecated. Use `geos.wkb_reader.read(data)`.",
|
|
DeprecationWarning)
|
|
return geom_factory(deserialize_wkb(data))
|
|
|
|
|
|
def geom_to_wkb(ob):
|
|
warn("`geom_to_wkb` is deprecated. Use `geos.wkb_writer.write(ob)`.",
|
|
DeprecationWarning)
|
|
if ob is None or ob._geom is None:
|
|
raise ValueError("Null geometry supports no operations")
|
|
size = c_size_t()
|
|
return lgeos.GEOSGeomToWKB_buf(c_void_p(ob._geom), pointer(size))
|
|
|
|
|
|
def geos_geom_from_py(ob, create_func=None):
|
|
"""Helper function for geos_*_from_py functions in each geom type.
|
|
|
|
If a create_func is specified the coodinate sequence is cloned and a new
|
|
geometry is created with it, otherwise the geometry is cloned directly.
|
|
This behaviour is useful for converting between LineString and LinearRing
|
|
objects.
|
|
"""
|
|
if create_func is None:
|
|
geom = lgeos.GEOSGeom_clone(ob._geom)
|
|
else:
|
|
cs = lgeos.GEOSGeom_getCoordSeq(ob._geom)
|
|
cs = lgeos.GEOSCoordSeq_clone(cs)
|
|
geom = create_func(cs)
|
|
|
|
N = ob._ndim
|
|
|
|
return geom, N
|
|
|
|
|
|
def exceptNull(func):
|
|
"""Decorator which helps avoid GEOS operations on null pointers."""
|
|
@wraps(func)
|
|
def wrapper(*args, **kwargs):
|
|
if not args[0]._geom or args[0].is_empty:
|
|
raise ValueError("Null/empty geometry supports no operations")
|
|
return func(*args, **kwargs)
|
|
return wrapper
|
|
|
|
|
|
class CAP_STYLE(object):
|
|
round = 1
|
|
flat = 2
|
|
square = 3
|
|
|
|
|
|
class JOIN_STYLE(object):
|
|
round = 1
|
|
mitre = 2
|
|
bevel = 3
|
|
|
|
EMPTY = deserialize_wkb(a2b_hex(b'010700000000000000'))
|
|
|
|
|
|
class BaseGeometry(object):
|
|
"""
|
|
Provides GEOS spatial predicates and topological operations.
|
|
|
|
"""
|
|
|
|
# Attributes
|
|
# ----------
|
|
# __geom__ : c_void_p
|
|
# Cached ctypes pointer to GEOS geometry. Not to be accessed.
|
|
# _geom : c_void_p
|
|
# Property by which the GEOS geometry is accessed.
|
|
# __p__ : object
|
|
# Parent (Shapely) geometry
|
|
# _ctypes_data : object
|
|
# Cached ctypes data buffer
|
|
# _ndim : int
|
|
# Number of dimensions (2 or 3, generally)
|
|
# _crs : object
|
|
# Coordinate reference system. Available for Shapely extensions, but
|
|
# not implemented here.
|
|
# _other_owned : bool
|
|
# True if this object's GEOS geometry is owned by another as in the
|
|
# case of a multipart geometry member.
|
|
__geom__ = EMPTY
|
|
__p__ = None
|
|
_ctypes_data = None
|
|
_ndim = None
|
|
_crs = None
|
|
_other_owned = False
|
|
_is_empty = True
|
|
|
|
# Backend config
|
|
impl = DefaultImplementation
|
|
|
|
# a reference to the so/dll proxy to preserve access during clean up
|
|
_lgeos = lgeos
|
|
|
|
def empty(self, val=EMPTY):
|
|
if not self._other_owned and self.__geom__ and self.__geom__ != EMPTY:
|
|
try:
|
|
self._lgeos.GEOSGeom_destroy(self.__geom__)
|
|
except (AttributeError, TypeError):
|
|
# _lgeos might be empty on shutdown
|
|
log.exception("Failed to delete GEOS geom")
|
|
|
|
self._is_empty = True
|
|
self.__geom__ = val
|
|
|
|
def __bool__(self):
|
|
return self.is_empty is False
|
|
|
|
def __nonzero__(self):
|
|
return self.__bool__()
|
|
|
|
def __del__(self):
|
|
self.empty(val=None)
|
|
self.__p__ = None
|
|
|
|
def __str__(self):
|
|
return self.wkt
|
|
|
|
# To support pickling
|
|
def __reduce__(self):
|
|
return (self.__class__, (), self.wkb)
|
|
|
|
def __setstate__(self, state):
|
|
self.empty()
|
|
self.__geom__ = deserialize_wkb(state)
|
|
self._is_empty = False
|
|
if lgeos.methods['has_z'](self.__geom__):
|
|
self._ndim = 3
|
|
else:
|
|
self._ndim = 2
|
|
|
|
@property
|
|
def _geom(self):
|
|
return self.__geom__
|
|
|
|
@_geom.setter
|
|
def _geom(self, val):
|
|
self.empty()
|
|
self._is_empty = val in [EMPTY, None]
|
|
self.__geom__ = val
|
|
|
|
# Operators
|
|
# ---------
|
|
|
|
def __and__(self, other):
|
|
return self.intersection(other)
|
|
|
|
def __or__(self, other):
|
|
return self.union(other)
|
|
|
|
def __sub__(self, other):
|
|
return self.difference(other)
|
|
|
|
def __xor__(self, other):
|
|
return self.symmetric_difference(other)
|
|
|
|
def __eq__(self, other):
|
|
return (
|
|
type(other) == type(self) and
|
|
tuple(self.coords) == tuple(other.coords)
|
|
)
|
|
|
|
def __ne__(self, other):
|
|
return not self.__eq__(other)
|
|
|
|
__hash__ = None
|
|
|
|
# Array and ctypes interfaces
|
|
# ---------------------------
|
|
|
|
@property
|
|
def ctypes(self):
|
|
"""Return ctypes buffer"""
|
|
raise NotImplementedError
|
|
|
|
@property
|
|
def array_interface_base(self):
|
|
if sys.byteorder == 'little':
|
|
typestr = '<f8'
|
|
elif sys.byteorder == 'big':
|
|
typestr = '>f8'
|
|
else:
|
|
raise ValueError(
|
|
"Unsupported byteorder: neither little nor big-endian")
|
|
return {
|
|
'version': 3,
|
|
'typestr': typestr,
|
|
'data': self.ctypes,
|
|
}
|
|
|
|
@property
|
|
def __array_interface__(self):
|
|
"""Provide the Numpy array protocol."""
|
|
raise NotImplementedError
|
|
|
|
# Coordinate access
|
|
# -----------------
|
|
|
|
def _get_coords(self):
|
|
"""Access to geometry's coordinates (CoordinateSequence)"""
|
|
if self.is_empty:
|
|
return []
|
|
return CoordinateSequence(self)
|
|
|
|
def _set_coords(self, ob):
|
|
raise NotImplementedError(
|
|
"set_coords must be provided by derived classes")
|
|
|
|
coords = property(_get_coords, _set_coords)
|
|
|
|
@property
|
|
def xy(self):
|
|
"""Separate arrays of X and Y coordinate values"""
|
|
raise NotImplementedError
|
|
|
|
# Python feature protocol
|
|
|
|
@property
|
|
def __geo_interface__(self):
|
|
"""Dictionary representation of the geometry"""
|
|
raise NotImplementedError
|
|
|
|
# Type of geometry and its representations
|
|
# ----------------------------------------
|
|
|
|
def geometryType(self):
|
|
return geometry_type_name(self._geom)
|
|
|
|
@property
|
|
def type(self):
|
|
return self.geometryType()
|
|
|
|
def to_wkb(self):
|
|
warn("`to_wkb` is deprecated. Use the `wkb` property.",
|
|
DeprecationWarning)
|
|
return geom_to_wkb(self)
|
|
|
|
def to_wkt(self):
|
|
warn("`to_wkt` is deprecated. Use the `wkt` property.",
|
|
DeprecationWarning)
|
|
return geom_to_wkt(self)
|
|
|
|
@property
|
|
def wkt(self):
|
|
"""WKT representation of the geometry"""
|
|
return WKTWriter(lgeos).write(self)
|
|
|
|
@property
|
|
def wkb(self):
|
|
"""WKB representation of the geometry"""
|
|
return WKBWriter(lgeos).write(self)
|
|
|
|
@property
|
|
def wkb_hex(self):
|
|
"""WKB hex representation of the geometry"""
|
|
return WKBWriter(lgeos).write_hex(self)
|
|
|
|
def svg(self, scale_factor=1., **kwargs):
|
|
"""Raises NotImplementedError"""
|
|
raise NotImplementedError
|
|
|
|
def _repr_svg_(self):
|
|
"""SVG representation for iPython notebook"""
|
|
svg_top = '<svg xmlns="http://www.w3.org/2000/svg" ' \
|
|
'xmlns:xlink="http://www.w3.org/1999/xlink" '
|
|
if self.is_empty:
|
|
return svg_top + '/>'
|
|
else:
|
|
# Establish SVG canvas that will fit all the data + small space
|
|
xmin, ymin, xmax, ymax = self.bounds
|
|
if xmin == xmax and ymin == ymax:
|
|
# This is a point; buffer using an arbitrary size
|
|
xmin, ymin, xmax, ymax = self.buffer(1).bounds
|
|
else:
|
|
# Expand bounds by a fraction of the data ranges
|
|
expand = 0.04 # or 4%, same as R plots
|
|
widest_part = max([xmax - xmin, ymax - ymin])
|
|
expand_amount = widest_part * expand
|
|
xmin -= expand_amount
|
|
ymin -= expand_amount
|
|
xmax += expand_amount
|
|
ymax += expand_amount
|
|
dx = xmax - xmin
|
|
dy = ymax - ymin
|
|
width = min([max([100., dx]), 300])
|
|
height = min([max([100., dy]), 300])
|
|
try:
|
|
scale_factor = max([dx, dy]) / max([width, height])
|
|
except ZeroDivisionError:
|
|
scale_factor = 1.
|
|
view_box = "{} {} {} {}".format(xmin, ymin, dx, dy)
|
|
transform = "matrix(1,0,0,-1,0,{})".format(ymax + ymin)
|
|
return svg_top + (
|
|
'width="{1}" height="{2}" viewBox="{0}" '
|
|
'preserveAspectRatio="xMinYMin meet">'
|
|
'<g transform="{3}">{4}</g></svg>'
|
|
).format(view_box, width, height, transform,
|
|
self.svg(scale_factor))
|
|
|
|
@property
|
|
def geom_type(self):
|
|
"""Name of the geometry's type, such as 'Point'"""
|
|
return self.geometryType()
|
|
|
|
# Real-valued properties and methods
|
|
# ----------------------------------
|
|
|
|
@property
|
|
def area(self):
|
|
"""Unitless area of the geometry (float)"""
|
|
return self.impl['area'](self)
|
|
|
|
def distance(self, other):
|
|
"""Unitless distance to other geometry (float)"""
|
|
return self.impl['distance'](self, other)
|
|
|
|
def hausdorff_distance(self, other):
|
|
"""Unitless hausdorff distance to other geometry (float)"""
|
|
return self.impl['hausdorff_distance'](self, other)
|
|
|
|
@property
|
|
def length(self):
|
|
"""Unitless length of the geometry (float)"""
|
|
return self.impl['length'](self)
|
|
|
|
@property
|
|
def minimum_clearance(self):
|
|
"""Unitless distance by which a node could be moved to produce an invalid geometry (float)"""
|
|
return self.impl['minimum_clearance'](self)
|
|
|
|
# Topological properties
|
|
# ----------------------
|
|
|
|
@property
|
|
def boundary(self):
|
|
"""Returns a lower dimension geometry that bounds the object
|
|
|
|
The boundary of a polygon is a line, the boundary of a line is a
|
|
collection of points. The boundary of a point is an empty (null)
|
|
collection.
|
|
"""
|
|
return geom_factory(self.impl['boundary'](self))
|
|
|
|
@property
|
|
def bounds(self):
|
|
"""Returns minimum bounding region (minx, miny, maxx, maxy)"""
|
|
if self.is_empty:
|
|
return ()
|
|
else:
|
|
return self.impl['bounds'](self)
|
|
|
|
@property
|
|
def centroid(self):
|
|
"""Returns the geometric center of the object"""
|
|
return geom_factory(self.impl['centroid'](self))
|
|
|
|
@delegated
|
|
def representative_point(self):
|
|
"""Returns a point guaranteed to be within the object, cheaply."""
|
|
return geom_factory(self.impl['representative_point'](self))
|
|
|
|
@property
|
|
def convex_hull(self):
|
|
"""Imagine an elastic band stretched around the geometry: that's a
|
|
convex hull, more or less
|
|
|
|
The convex hull of a three member multipoint, for example, is a
|
|
triangular polygon.
|
|
"""
|
|
return geom_factory(self.impl['convex_hull'](self))
|
|
|
|
@property
|
|
def envelope(self):
|
|
"""A figure that envelopes the geometry"""
|
|
return geom_factory(self.impl['envelope'](self))
|
|
|
|
@property
|
|
def minimum_rotated_rectangle(self):
|
|
"""Returns the general minimum bounding rectangle of
|
|
the geometry. Can possibly be rotated. If the convex hull
|
|
of the object is a degenerate (line or point) this same degenerate
|
|
is returned.
|
|
"""
|
|
# first compute the convex hull
|
|
hull = self.convex_hull
|
|
try:
|
|
coords = hull.exterior.coords
|
|
except AttributeError: # may be a Point or a LineString
|
|
return hull
|
|
# generate the edge vectors between the convex hull's coords
|
|
edges = ((pt2[0] - pt1[0], pt2[1] - pt1[1]) for pt1, pt2 in zip(
|
|
coords, islice(coords, 1, None)))
|
|
|
|
def _transformed_rects():
|
|
for dx, dy in edges:
|
|
# compute the normalized direction vector of the edge
|
|
# vector.
|
|
length = math.sqrt(dx ** 2 + dy ** 2)
|
|
ux, uy = dx / length, dy / length
|
|
# compute the normalized perpendicular vector
|
|
vx, vy = -uy, ux
|
|
# transform hull from the original coordinate system to
|
|
# the coordinate system defined by the edge and compute
|
|
# the axes-parallel bounding rectangle.
|
|
transf_rect = affine_transform(
|
|
hull, (ux, uy, vx, vy, 0, 0)).envelope
|
|
# yield the transformed rectangle and a matrix to
|
|
# transform it back to the original coordinate system.
|
|
yield (transf_rect, (ux, vx, uy, vy, 0, 0))
|
|
|
|
# check for the minimum area rectangle and return it
|
|
transf_rect, inv_matrix = min(
|
|
_transformed_rects(), key=lambda r: r[0].area)
|
|
return affine_transform(transf_rect, inv_matrix)
|
|
|
|
def buffer(self, distance, resolution=16, quadsegs=None,
|
|
cap_style=CAP_STYLE.round, join_style=JOIN_STYLE.round,
|
|
mitre_limit=5.0, single_sided=False):
|
|
"""Get a geometry that represents all points within a distance
|
|
of this geometry.
|
|
|
|
A positive distance produces a dilation, a negative distance an
|
|
erosion. A very small or zero distance may sometimes be used to
|
|
"tidy" a polygon.
|
|
|
|
Parameters
|
|
----------
|
|
distance : float
|
|
The distance to buffer around the object.
|
|
resolution : int, optional
|
|
The resolution of the buffer around each vertex of the
|
|
object.
|
|
quadsegs : int, optional
|
|
Sets the number of line segments used to approximate an
|
|
angle fillet. Note: the use of a `quadsegs` parameter is
|
|
deprecated and will be gone from the next major release.
|
|
cap_style : int, optional
|
|
The styles of caps are: CAP_STYLE.round (1), CAP_STYLE.flat
|
|
(2), and CAP_STYLE.square (3).
|
|
join_style : int, optional
|
|
The styles of joins between offset segments are:
|
|
JOIN_STYLE.round (1), JOIN_STYLE.mitre (2), and
|
|
JOIN_STYLE.bevel (3).
|
|
mitre_limit : float, optional
|
|
The mitre limit ratio is used for very sharp corners. The
|
|
mitre ratio is the ratio of the distance from the corner to
|
|
the end of the mitred offset corner. When two line segments
|
|
meet at a sharp angle, a miter join will extend the original
|
|
geometry. To prevent unreasonable geometry, the mitre limit
|
|
allows controlling the maximum length of the join corner.
|
|
Corners with a ratio which exceed the limit will be beveled.
|
|
single_side : bool, optional
|
|
The side used is determined by the sign of the buffer
|
|
distance:
|
|
|
|
a positive distance indicates the left-hand side
|
|
a negative distance indicates the right-hand side
|
|
|
|
The single-sided buffer of point geometries is the same as
|
|
the regular buffer. The End Cap Style for single-sided
|
|
buffers is always ignored, and forced to the equivalent of
|
|
CAP_FLAT.
|
|
|
|
Returns
|
|
-------
|
|
Geometry
|
|
|
|
Notes
|
|
-----
|
|
The return value is a strictly two-dimensional geometry. All
|
|
Z coordinates of the original geometry will be ignored.
|
|
|
|
Examples
|
|
--------
|
|
>>> from shapely.wkt import loads
|
|
>>> g = loads('POINT (0.0 0.0)')
|
|
>>> g.buffer(1.0).area # 16-gon approx of a unit radius circle
|
|
3.1365484905459389
|
|
>>> g.buffer(1.0, 128).area # 128-gon approximation
|
|
3.1415138011443009
|
|
>>> g.buffer(1.0, 3).area # triangle approximation
|
|
3.0
|
|
>>> list(g.buffer(1.0, cap_style=CAP_STYLE.square).exterior.coords)
|
|
[(1.0, 1.0), (1.0, -1.0), (-1.0, -1.0), (-1.0, 1.0), (1.0, 1.0)]
|
|
>>> g.buffer(1.0, cap_style=CAP_STYLE.square).area
|
|
4.0
|
|
|
|
"""
|
|
if quadsegs is not None:
|
|
warn(
|
|
"The `quadsegs` argument is deprecated. Use `resolution`.",
|
|
DeprecationWarning)
|
|
res = quadsegs
|
|
else:
|
|
res = resolution
|
|
|
|
if mitre_limit == 0.0:
|
|
raise ValueError(
|
|
'Cannot compute offset from zero-length line segment')
|
|
|
|
if 'buffer_with_params' in self.impl:
|
|
params = self._lgeos.GEOSBufferParams_create()
|
|
self._lgeos.GEOSBufferParams_setEndCapStyle(params, cap_style)
|
|
self._lgeos.GEOSBufferParams_setJoinStyle(params, join_style)
|
|
self._lgeos.GEOSBufferParams_setMitreLimit(params, mitre_limit)
|
|
self._lgeos.GEOSBufferParams_setQuadrantSegments(params, res)
|
|
self._lgeos.GEOSBufferParams_setSingleSided(params, single_sided)
|
|
return geom_factory(self.impl['buffer_with_params'](self, params, distance))
|
|
|
|
if cap_style == CAP_STYLE.round and join_style == JOIN_STYLE.round:
|
|
return geom_factory(self.impl['buffer'](self, distance, res))
|
|
|
|
if 'buffer_with_style' not in self.impl:
|
|
raise NotImplementedError("Styled buffering not available for "
|
|
"GEOS versions < 3.2.")
|
|
|
|
return geom_factory(self.impl['buffer_with_style'](self, distance, res,
|
|
cap_style,
|
|
join_style,
|
|
mitre_limit))
|
|
|
|
@delegated
|
|
def simplify(self, tolerance, preserve_topology=True):
|
|
"""Returns a simplified geometry produced by the Douglas-Peucker
|
|
algorithm
|
|
|
|
Coordinates of the simplified geometry will be no more than the
|
|
tolerance distance from the original. Unless the topology preserving
|
|
option is used, the algorithm may produce self-intersecting or
|
|
otherwise invalid geometries.
|
|
"""
|
|
if preserve_topology:
|
|
op = self.impl['topology_preserve_simplify']
|
|
else:
|
|
op = self.impl['simplify']
|
|
return geom_factory(op(self, tolerance))
|
|
|
|
# Binary operations
|
|
# -----------------
|
|
|
|
def difference(self, other):
|
|
"""Returns the difference of the geometries"""
|
|
return geom_factory(self.impl['difference'](self, other))
|
|
|
|
def intersection(self, other):
|
|
"""Returns the intersection of the geometries"""
|
|
return geom_factory(self.impl['intersection'](self, other))
|
|
|
|
def symmetric_difference(self, other):
|
|
"""Returns the symmetric difference of the geometries
|
|
(Shapely geometry)"""
|
|
return geom_factory(self.impl['symmetric_difference'](self, other))
|
|
|
|
def union(self, other):
|
|
"""Returns the union of the geometries (Shapely geometry)"""
|
|
return geom_factory(self.impl['union'](self, other))
|
|
|
|
# Unary predicates
|
|
# ----------------
|
|
|
|
@property
|
|
def has_z(self):
|
|
"""True if the geometry's coordinate sequence(s) have z values (are
|
|
3-dimensional)"""
|
|
return bool(self.impl['has_z'](self))
|
|
|
|
@property
|
|
def is_empty(self):
|
|
"""True if the set of points in this geometry is empty, else False"""
|
|
return (self._geom is None) or bool(self.impl['is_empty'](self))
|
|
|
|
@property
|
|
def is_ring(self):
|
|
"""True if the geometry is a closed ring, else False"""
|
|
return bool(self.impl['is_ring'](self))
|
|
|
|
@property
|
|
def is_closed(self):
|
|
"""True if the geometry is closed, else False
|
|
|
|
Applicable only to 1-D geometries."""
|
|
if self.geom_type == 'LinearRing':
|
|
return True
|
|
elif self.geom_type == 'LineString':
|
|
if 'is_closed' in self.impl:
|
|
return bool(self.impl['is_closed'](self))
|
|
else:
|
|
return self.coords[0] == self.coords[-1]
|
|
else:
|
|
return False
|
|
|
|
@property
|
|
def is_simple(self):
|
|
"""True if the geometry is simple, meaning that any self-intersections
|
|
are only at boundary points, else False"""
|
|
return bool(self.impl['is_simple'](self))
|
|
|
|
@property
|
|
def is_valid(self):
|
|
"""True if the geometry is valid (definition depends on sub-class),
|
|
else False"""
|
|
return bool(self.impl['is_valid'](self))
|
|
|
|
# Binary predicates
|
|
# -----------------
|
|
|
|
def relate(self, other):
|
|
"""Returns the DE-9IM intersection matrix for the two geometries
|
|
(string)"""
|
|
return self.impl['relate'](self, other)
|
|
|
|
def covers(self, other):
|
|
"""Returns True if the geometry covers the other, else False"""
|
|
return bool(self.impl['covers'](self, other))
|
|
|
|
def contains(self, other):
|
|
"""Returns True if the geometry contains the other, else False"""
|
|
return bool(self.impl['contains'](self, other))
|
|
|
|
def crosses(self, other):
|
|
"""Returns True if the geometries cross, else False"""
|
|
return bool(self.impl['crosses'](self, other))
|
|
|
|
def disjoint(self, other):
|
|
"""Returns True if geometries are disjoint, else False"""
|
|
return bool(self.impl['disjoint'](self, other))
|
|
|
|
def equals(self, other):
|
|
"""Returns True if geometries are equal, else False
|
|
|
|
Refers to point-set equality (or topological equality), and is equivalent to
|
|
(self.within(other) & self.contains(other))
|
|
"""
|
|
return bool(self.impl['equals'](self, other))
|
|
|
|
def intersects(self, other):
|
|
"""Returns True if geometries intersect, else False"""
|
|
return bool(self.impl['intersects'](self, other))
|
|
|
|
def overlaps(self, other):
|
|
"""Returns True if geometries overlap, else False"""
|
|
return bool(self.impl['overlaps'](self, other))
|
|
|
|
def touches(self, other):
|
|
"""Returns True if geometries touch, else False"""
|
|
return bool(self.impl['touches'](self, other))
|
|
|
|
def within(self, other):
|
|
"""Returns True if geometry is within the other, else False"""
|
|
return bool(self.impl['within'](self, other))
|
|
|
|
def equals_exact(self, other, tolerance):
|
|
"""Returns True if geometries are equal to within a specified
|
|
tolerance
|
|
|
|
Refers to coordinate equality, which requires coordinates to be equal
|
|
and in the same order for all components of a geometry
|
|
"""
|
|
return bool(self.impl['equals_exact'](self, other, tolerance))
|
|
|
|
def almost_equals(self, other, decimal=6):
|
|
"""Returns True if geometries are equal at all coordinates to a
|
|
specified decimal place
|
|
|
|
Refers to approximate coordinate equality, which requires coordinates be
|
|
approximately equal and in the same order for all components of a geometry.
|
|
"""
|
|
return self.equals_exact(other, 0.5 * 10**(-decimal))
|
|
|
|
def relate_pattern(self, other, pattern):
|
|
"""Returns True if the DE-9IM string code for the relationship between
|
|
the geometries satisfies the pattern, else False"""
|
|
pattern = c_char_p(pattern.encode('ascii'))
|
|
return bool(self.impl['relate_pattern'](self, other, pattern))
|
|
|
|
# Linear referencing
|
|
# ------------------
|
|
|
|
@delegated
|
|
def project(self, other, normalized=False):
|
|
"""Returns the distance along this geometry to a point nearest the
|
|
specified point
|
|
|
|
If the normalized arg is True, return the distance normalized to the
|
|
length of the linear geometry.
|
|
"""
|
|
if normalized:
|
|
op = self.impl['project_normalized']
|
|
else:
|
|
op = self.impl['project']
|
|
return op(self, other)
|
|
|
|
@delegated
|
|
@exceptNull
|
|
def interpolate(self, distance, normalized=False):
|
|
"""Return a point at the specified distance along a linear geometry
|
|
|
|
Negative length values are taken as measured in the reverse
|
|
direction from the end of the geometry. Out-of-range index
|
|
values are handled by clamping them to the valid range of values.
|
|
If the normalized arg is True, the distance will be interpreted as a
|
|
fraction of the geometry's length.
|
|
"""
|
|
if normalized:
|
|
op = self.impl['interpolate_normalized']
|
|
else:
|
|
op = self.impl['interpolate']
|
|
return geom_factory(op(self, distance))
|
|
|
|
|
|
class BaseMultipartGeometry(BaseGeometry):
|
|
|
|
def shape_factory(self, *args):
|
|
# Factory for part instances, usually a geometry class
|
|
raise NotImplementedError("To be implemented by derived classes")
|
|
|
|
@property
|
|
def ctypes(self):
|
|
raise NotImplementedError(
|
|
"Multi-part geometries have no ctypes representations")
|
|
|
|
@property
|
|
def __array_interface__(self):
|
|
"""Provide the Numpy array protocol."""
|
|
raise NotImplementedError("Multi-part geometries do not themselves "
|
|
"provide the array interface")
|
|
|
|
def _get_coords(self):
|
|
raise NotImplementedError("Sub-geometries may have coordinate "
|
|
"sequences, but collections do not")
|
|
|
|
def _set_coords(self, ob):
|
|
raise NotImplementedError("Sub-geometries may have coordinate "
|
|
"sequences, but collections do not")
|
|
|
|
@property
|
|
def coords(self):
|
|
raise NotImplementedError(
|
|
"Multi-part geometries do not provide a coordinate sequence")
|
|
|
|
@property
|
|
def geoms(self):
|
|
if self.is_empty:
|
|
return []
|
|
return GeometrySequence(self, self.shape_factory)
|
|
|
|
def __bool__(self):
|
|
return self.is_empty is False
|
|
|
|
def __iter__(self):
|
|
if not self.is_empty:
|
|
return iter(self.geoms)
|
|
else:
|
|
return iter([])
|
|
|
|
def __len__(self):
|
|
if not self.is_empty:
|
|
return len(self.geoms)
|
|
else:
|
|
return 0
|
|
|
|
def __getitem__(self, index):
|
|
if not self.is_empty:
|
|
return self.geoms[index]
|
|
else:
|
|
return ()[index]
|
|
|
|
def __eq__(self, other):
|
|
return (
|
|
type(other) == type(self) and
|
|
len(self) == len(other) and
|
|
all(x == y for x, y in zip(self, other))
|
|
)
|
|
|
|
def __ne__(self, other):
|
|
return not self.__eq__(other)
|
|
|
|
__hash__ = None
|
|
|
|
def svg(self, scale_factor=1., color=None):
|
|
"""Returns a group of SVG elements for the multipart geometry.
|
|
|
|
Parameters
|
|
==========
|
|
scale_factor : float
|
|
Multiplication factor for the SVG stroke-width. Default is 1.
|
|
color : str, optional
|
|
Hex string for stroke or fill color. Default is to use "#66cc99"
|
|
if geometry is valid, and "#ff3333" if invalid.
|
|
"""
|
|
if self.is_empty:
|
|
return '<g />'
|
|
if color is None:
|
|
color = "#66cc99" if self.is_valid else "#ff3333"
|
|
return '<g>' + \
|
|
''.join(p.svg(scale_factor, color) for p in self) + \
|
|
'</g>'
|
|
|
|
|
|
class GeometrySequence(object):
|
|
"""
|
|
Iterative access to members of a homogeneous multipart geometry.
|
|
"""
|
|
|
|
# Attributes
|
|
# ----------
|
|
# _factory : callable
|
|
# Returns instances of Shapely geometries
|
|
# _geom : c_void_p
|
|
# Ctypes pointer to the parent's GEOS geometry
|
|
# _ndim : int
|
|
# Number of dimensions (2 or 3, generally)
|
|
# __p__ : object
|
|
# Parent (Shapely) geometry
|
|
shape_factory = None
|
|
_geom = None
|
|
__p__ = None
|
|
_ndim = None
|
|
|
|
def __init__(self, parent, type):
|
|
self.shape_factory = type
|
|
self.__p__ = parent
|
|
|
|
def _update(self):
|
|
self._geom = self.__p__._geom
|
|
self._ndim = self.__p__._ndim
|
|
|
|
def _get_geom_item(self, i):
|
|
g = self.shape_factory()
|
|
g._other_owned = True
|
|
g._geom = lgeos.GEOSGetGeometryN(self._geom, i)
|
|
g._ndim = self._ndim
|
|
g.__p__ = self
|
|
return g
|
|
|
|
def __iter__(self):
|
|
self._update()
|
|
for i in range(self.__len__()):
|
|
yield self._get_geom_item(i)
|
|
|
|
def __len__(self):
|
|
self._update()
|
|
return lgeos.GEOSGetNumGeometries(self._geom)
|
|
|
|
def __getitem__(self, key):
|
|
self._update()
|
|
m = self.__len__()
|
|
if isinstance(key, integer_types):
|
|
if key + m < 0 or key >= m:
|
|
raise IndexError("index out of range")
|
|
if key < 0:
|
|
i = m + key
|
|
else:
|
|
i = key
|
|
return self._get_geom_item(i)
|
|
elif isinstance(key, slice):
|
|
if type(self) == HeterogeneousGeometrySequence:
|
|
raise TypeError(
|
|
"Heterogenous geometry collections are not sliceable")
|
|
res = []
|
|
start, stop, stride = key.indices(m)
|
|
for i in range(start, stop, stride):
|
|
res.append(self._get_geom_item(i))
|
|
return type(self.__p__)(res or None)
|
|
else:
|
|
raise TypeError("key must be an index or slice")
|
|
|
|
@property
|
|
def _longest(self):
|
|
max = 0
|
|
for g in iter(self):
|
|
l = len(g.coords)
|
|
if l > max:
|
|
max = l
|
|
|
|
|
|
class HeterogeneousGeometrySequence(GeometrySequence):
|
|
"""
|
|
Iterative access to a heterogeneous sequence of geometries.
|
|
"""
|
|
|
|
def __init__(self, parent):
|
|
super(HeterogeneousGeometrySequence, self).__init__(parent, None)
|
|
|
|
def _get_geom_item(self, i):
|
|
sub = lgeos.GEOSGetGeometryN(self._geom, i)
|
|
g = geom_factory(sub, parent=self)
|
|
g._other_owned = True
|
|
return g
|
|
|
|
|
|
class EmptyGeometry(BaseGeometry):
|
|
def __init__(self):
|
|
"""Create an empty geometry."""
|
|
BaseGeometry.__init__(self)
|
|
|
|
|
|
def _test():
|
|
"""Test runner"""
|
|
import doctest
|
|
doctest.testmod()
|
|
|
|
if __name__ == "__main__":
|
|
_test()
|