"""
Created on Wed Jul 18 10:46:25 2012
@author: pietro
"""
import ctypes
import re
from collections import namedtuple
import numpy as np
import grass.lib.gis as libgis
import grass.lib.vector as libvect
from grass.pygrass.utils import decode
from grass.pygrass.errors import GrassError, mapinfo_must_be_set
from grass.pygrass.vector.basic import Ilist, Bbox, Cats
from grass.pygrass.vector import sql
# For test purposes
test_vector_name = "geometry_doctest_map"
LineDist = namedtuple("LineDist", "point dist spdist sldist")
WKT = {
"POINT\((.*)\)": "point", # 'POINT\(\s*([+-]*\d+\.*\d*)+\s*\)'
"LINESTRING\((.*)\)": "line",
}
[docs]def read_WKT(string):
"""Read the string and return a geometry object
**WKT**:
::
POINT(0 0)
LINESTRING(0 0,1 1,1 2)
POLYGON((0 0,4 0,4 4,0 4,0 0),(1 1, 2 1, 2 2, 1 2,1 1))
MULTIPOINT(0 0,1 2)
MULTILINESTRING((0 0,1 1,1 2),(2 3,3 2,5 4))
MULTIPOLYGON(((0 0,4 0,4 4,0 4,0 0),(1 1,2 1,2 2,1 2,1 1)),
((-1 -1,-1 -2,-2 -2,-2 -1,-1 -1)))
GEOMETRYCOLLECTION(POINT(2 3),LINESTRING(2 3,3 4))
**EWKT**:
::
POINT(0 0 0) -- XYZ
SRID=32632;POINT(0 0) -- XY with SRID
POINTM(0 0 0) -- XYM
POINT(0 0 0 0) -- XYZM
SRID=4326;MULTIPOINTM(0 0 0,1 2 1) -- XYM with SRID
MULTILINESTRING((0 0 0,1 1 0,1 2 1),(2 3 1,3 2 1,5 4 1))
POLYGON((0 0 0,4 0 0,4 4 0,0 4 0,0 0 0),(1 1 0,2 1 0,2 2 0,1 2 0,1 1 0))
MULTIPOLYGON(((0 0 0,4 0 0,4 4 0,0 4 0,0 0 0),
(1 1 0,2 1 0,2 2 0,1 2 0,1 1 0)),
((-1 -1 0,-1 -2 0,-2 -2 0,-2 -1 0,-1 -1 0)))
GEOMETRYCOLLECTIONM( POINTM(2 3 9), LINESTRINGM(2 3 4, 3 4 5) )
MULTICURVE( (0 0, 5 5), CIRCULARSTRING(4 0, 4 4, 8 4) )
POLYHEDRALSURFACE( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)),
((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)),
((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),
((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)),
((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)),
((0 0 1, 1 0 1, 1 1 1, 0 1 1, 0 0 1)) )
TRIANGLE ((0 0, 0 9, 9 0, 0 0))
TIN( ((0 0 0, 0 0 1, 0 1 0, 0 0 0)), ((0 0 0, 0 1 0, 1 1 0, 0 0 0)) )
"""
for regexp, obj in WKT.items():
if re.match(regexp, string):
geo = 10
return obj(geo)
[docs]def read_WKB(buff):
"""Read the binary buffer and return a geometry object"""
pass
[docs]def intersects(lineA, lineB, with_z=False):
"""Return a list of points
>>> lineA = Line([(0, 0), (4, 0)])
>>> lineB = Line([(2, 2), (2, -2)])
>>> intersects(lineA, lineB)
Line([Point(2.000000, 0.000000)])
"""
line = Line()
if libvect.Vect_line_get_intersections(
lineA.c_points, lineB.c_points, line.c_points, int(with_z)
):
return line
else:
return []
# =============================================
# GEOMETRY
# =============================================
[docs]def get_xyz(pnt):
"""Return a tuple with: x, y, z.
>>> pnt = Point(0, 0)
>>> get_xyz(pnt)
(0.0, 0.0, 0.0)
>>> get_xyz((1, 1))
(1, 1, 0.0)
>>> get_xyz((1, 1, 2))
(1, 1, 2)
>>> get_xyz((1, 1, 2, 2)) #doctest: +ELLIPSIS
Traceback (most recent call last):
...
ValueError: The the format of the point is not supported: (1, 1, 2, 2)
"""
if isinstance(pnt, Point):
if pnt.is2D:
x, y = pnt.x, pnt.y
z = 0.0
else:
x, y, z = pnt.x, pnt.y, pnt.z
else:
if len(pnt) == 2:
x, y = pnt
z = 0.0
elif len(pnt) == 3:
x, y, z = pnt
else:
str_error = "The the format of the point is not supported: {0!r}"
raise ValueError(str_error.format(pnt))
return x, y, z
[docs]class Attrs(object):
def __init__(self, cat, table, writeable=False):
self._cat = None
self.cond = ""
self.table = table
self.cat = cat
self.writeable = writeable
def _get_cat(self):
return self._cat
def _set_cat(self, value):
self._cat = value
if value:
# update condition
self.cond = "%s=%d" % (self.table.key, value)
cat = property(fget=_get_cat, fset=_set_cat, doc="Set and obtain cat value")
def __getitem__(self, keys):
"""Return the value stored in the attribute table.
>>> from grass.pygrass.vector import VectorTopo
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
>>> v1 = test_vect[1]
>>> v1.attrs['name']
'point'
>>> v1.attrs['name', 'value']
('point', 1.0)
>>> test_vect.close()
"""
sqlcode = sql.SELECT_WHERE.format(
cols=(keys if np.isscalar(keys) else ", ".join(keys)),
tname=self.table.name,
condition=self.cond,
)
cur = self.table.execute(sqlcode)
results = cur.fetchone()
if results is not None:
return results[0] if len(results) == 1 else results
def __setitem__(self, keys, values):
"""Set value of a given column of a table attribute.
>>> from grass.pygrass.vector import VectorTopo
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
>>> v1 = test_vect[1]
>>> v1.attrs['name']
'point'
>>> v1.attrs['name'] = "new_point_1"
>>> v1.attrs['name']
'new_point_1'
>>> v1.attrs['name', 'value'] = "new_point_2", 100.
>>> v1.attrs['name', 'value']
('new_point_2', 100.0)
>>> v1.attrs['name', 'value'] = "point", 1.
>>> v1.attrs.table.conn.commit()
>>> test_vect.close()
"""
if self.writeable:
if np.isscalar(keys):
keys, values = (keys,), (values,)
# check if key is a column of the table or not
for key in keys:
if key not in self.table.columns:
raise KeyError("Column: %s not in table" % key)
# prepare the string using as paramstyle: qmark
vals = ",".join(["%s=?" % k for k in keys])
# "UPDATE {tname} SET {values} WHERE {condition};"
sqlcode = sql.UPDATE_WHERE.format(
tname=self.table.name, values=vals, condition=self.cond
)
self.table.execute(sqlcode, values=values)
# self.table.conn.commit()
else:
str_err = "You can only read the attributes if the map is in another mapset"
raise GrassError(str_err)
def __dict__(self):
"""Return a dict of the attribute table row."""
dic = {}
for key, val in zip(self.keys(), self.values()):
dic[key] = val
return dic
[docs] def values(self):
"""Return the values of the attribute table row.
>>> from grass.pygrass.vector import VectorTopo
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
>>> v1 = test_vect[1]
>>> v1.attrs.values()
(1, 'point', 1.0)
>>> test_vect.close()
"""
# SELECT {cols} FROM {tname} WHERE {condition}
cur = self.table.execute(
sql.SELECT_WHERE.format(
cols="*", tname=self.table.name, condition=self.cond
)
)
return cur.fetchone()
[docs] def keys(self):
"""Return the column name of the attribute table.
>>> from grass.pygrass.vector import VectorTopo
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
>>> v1 = test_vect[1]
>>> v1.attrs.keys()
['cat', 'name', 'value']
>>> test_vect.close()
"""
return self.table.columns.names()
[docs] def commit(self):
"""Save the changes"""
self.table.conn.commit()
[docs]class Geo(object):
"""
Base object for different feature types
"""
gtype = None
def __init__(
self,
v_id=0,
c_mapinfo=None,
c_points=None,
c_cats=None,
table=None,
writeable=False,
is2D=True,
free_points=False,
free_cats=False,
):
"""Constructor of a geometry object
:param v_id: The vector feature id
:param c_mapinfo: A pointer to the vector mapinfo structure
:param c_points: A pointer to a libvect.line_pnts structure, this
is optional, if not set an internal structure will
be allocated and free'd at object destruction
:param c_cats: A pointer to a libvect.line_cats structure, this
is optional, if not set an internal structure will
be allocated and free'd at object destruction
:param table: The attribute table to select attributes for
this feature
:param writeable: Not sure what this is for?
:param is2D: If True this feature has two dimensions, False if
this feature has three dimensions
:param free_points: Set this True if the provided c_points structure
should be free'd at object destruction, be aware
that no other object should free them, otherwise
you can expect a double free corruption segfault
:param free_cats: Set this True if the provided c_cats structure
should be free'd at object destruction, be aware
that no other object should free them, otherwise
you can expect a double free corruption segfault
"""
self.id = v_id # vector id
self.c_mapinfo = c_mapinfo
self.is2D = (
is2D if is2D is not None else bool(libvect.Vect_is_3d(self.c_mapinfo) != 1)
)
# Set True if cats and points are allocated by this object
# to free the cats and points structures on destruction
self._free_points = False
self._free_cats = False
read = False
# set c_points
if c_points is None:
self.c_points = ctypes.pointer(libvect.line_pnts())
self._free_points = True
read = True
else:
self.c_points = c_points
self._free_points = free_points
# set c_cats
if c_cats is None:
self.c_cats = ctypes.pointer(libvect.line_cats())
self._free_cats = free_cats
read = True
else:
self.c_cats = c_cats
self._free_cats = True
if self.id and self.c_mapinfo is not None and read:
self.read()
# set the attributes as last thing to do
self.attrs = None
if table is not None and self.cat is not None:
self.attrs = Attrs(self.cat, table, writeable)
def __del__(self):
"""Take care of the allocated line_pnts and line_cats allocation"""
if self._free_points is True and self.c_points:
if self.c_points.contents.alloc_points > 0:
# print("G_free(points) [%i]"%(self.c_points.contents.alloc_points))
libgis.G_free(self.c_points.contents.x)
libgis.G_free(self.c_points.contents.y)
if self.c_points.contents.z:
libgis.G_free(self.c_points.contents.z)
if self._free_cats is True and self.c_cats:
if self.c_cats.contents.alloc_cats > 0:
# print("G_free(cats) [%i]"%(self.c_cats.contents.alloc_cats))
libgis.G_free(self.c_cats.contents.cat)
@property
def cat(self):
if self.c_cats.contents.cat:
return self.c_cats.contents.cat.contents.value
[docs] def has_topology(self):
if self.c_mapinfo is not None:
return self.c_mapinfo.contents.level == 2
else:
return False
[docs] @mapinfo_must_be_set
def read(self):
"""Read and set the coordinates of the centroid from the vector map,
using the centroid_id and calling the Vect_read_line C function"""
self.id, ftype, c_points, c_cats = c_read_line(
self.id, self.c_mapinfo, self.c_points, self.c_cats
)
[docs] def to_wkt(self):
"""Return a "well know text" (WKT) geometry string, this method uses
the GEOS implementation in the vector library. ::
>>> pnt = Point(10, 100)
>>> pnt.to_wkt()
'POINT (10.0000000000000000 100.0000000000000000)'
"""
return decode(
libvect.Vect_line_to_wkt(self.c_points, self.gtype, not self.is2D)
)
[docs] def to_wkb(self):
"""Return a "well know binary" (WKB) geometry byte array, this method uses
the GEOS implementation in the vector library. ::
>>> pnt = Point(10, 100)
>>> wkb = pnt.to_wkb()
>>> len(wkb)
21
"""
size = ctypes.c_size_t()
barray = libvect.Vect_line_to_wkb(
self.c_points, self.gtype, not self.is2D, ctypes.byref(size)
)
return ctypes.string_at(barray, size.value)
[docs]class Point(Geo):
"""Instantiate a Point object that could be 2 or 3D, default
parameters are 0.
::
>>> pnt = Point()
>>> pnt.x
0.0
>>> pnt.y
0.0
>>> pnt.z
>>> pnt.is2D
True
>>> pnt
Point(0.000000, 0.000000)
>>> pnt.z = 0
>>> pnt.is2D
False
>>> pnt
Point(0.000000, 0.000000, 0.000000)
>>> print(pnt)
POINT Z (0.0000000000000000 0.0000000000000000 0.0000000000000000)
>>> c_points = ctypes.pointer(libvect.line_pnts())
>>> c_cats = ctypes.pointer(libvect.line_cats())
>>> p = Point(c_points = c_points, c_cats=c_cats)
>>> del p
>>> c_points = ctypes.pointer(libvect.line_pnts())
>>> c_cats = ctypes.pointer(libvect.line_cats())
>>> p = Point(c_points=c_points, c_cats=c_cats, free_points=True,
... free_cats=True)
>>> del p
..
"""
# geometry type
gtype = libvect.GV_POINT
def __init__(self, x=0, y=0, z=None, **kargs):
super(Point, self).__init__(**kargs)
if self.id and self.c_mapinfo:
self.read()
else:
self.is2D = True if z is None else False
z = z if z is not None else 0
libvect.Vect_append_point(self.c_points, x, y, z)
def _get_x(self):
return self.c_points.contents.x[0]
def _set_x(self, value):
self.c_points.contents.x[0] = value
x = property(fget=_get_x, fset=_set_x, doc="Set and obtain x coordinate")
def _get_y(self):
return self.c_points.contents.y[0]
def _set_y(self, value):
self.c_points.contents.y[0] = value
y = property(fget=_get_y, fset=_set_y, doc="Set and obtain y coordinate")
def _get_z(self):
if self.is2D:
return None
return self.c_points.contents.z[0]
def _set_z(self, value):
if value is None:
self.is2D = True
self.c_points.contents.z[0] = 0
else:
self.c_points.contents.z[0] = value
self.is2D = False
z = property(fget=_get_z, fset=_set_z, doc="Set and obtain z coordinate")
def __str__(self):
return self.to_wkt()
def __repr__(self):
return "Point(%s)" % ", ".join(["%f" % coor for coor in self.coords()])
def __eq__(self, pnt):
"""Return True if the coordinates are the same.
>>> p0 = Point()
>>> p1 = Point()
>>> p2 = Point(1, 1)
>>> p0 == p1
True
>>> p1 == p2
False
"""
if isinstance(pnt, Point):
return pnt.coords() == self.coords()
return Point(*pnt).coords() == self.coords()
def __ne__(self, other):
return not self == other
# Restore Python 2 hashing behaviour on Python 3
__hash__ = object.__hash__
[docs] def coords(self):
"""Return a tuple with the point coordinates. ::
>>> pnt = Point(10, 100)
>>> pnt.coords()
(10.0, 100.0)
If the point is 2D return a x, y tuple. But if we change the ``z``
the Point object become a 3D point, therefore the method return a
x, y, z tuple. ::
>>> pnt.z = 1000.
>>> pnt.coords()
(10.0, 100.0, 1000.0)
..
"""
if self.is2D:
return self.x, self.y
else:
return self.x, self.y, self.z
[docs] def to_wkt_p(self):
"""Return a "well know text" (WKT) geometry string Python implementation. ::
>>> pnt = Point(10, 100)
>>> pnt.to_wkt_p()
'POINT(10.000000 100.000000)'
.. warning::
Only ``POINT`` (2/3D) are supported, ``POINTM`` and ``POINT`` with:
``XYZM`` are not supported yet.
"""
return "POINT(%s)" % " ".join(["%f" % coord for coord in self.coords()])
[docs] def distance(self, pnt):
"""Calculate distance of 2 points, using the Vect_points_distance
C function, If one of the point have z == None, return the 2D distance.
:param pnt: the point for calculate the distance
:type pnt: a Point object or a tuple with the coordinates
>>> pnt0 = Point(0, 0, 0)
>>> pnt1 = Point(1, 0)
>>> pnt0.distance(pnt1)
1.0
>>> pnt1.z = 1
>>> pnt1
Point(1.000000, 0.000000, 1.000000)
>>> pnt0.distance(pnt1)
1.4142135623730951
"""
if self.is2D or pnt.is2D:
return libvect.Vect_points_distance(self.x, self.y, 0, pnt.x, pnt.y, 0, 0)
else:
return libvect.Vect_points_distance(
self.x, self.y, self.z, pnt.x, pnt.y, pnt.z, 1
)
[docs] def buffer(
self, dist=None, dist_x=None, dist_y=None, angle=0, round_=True, tol=0.1
):
"""Return the buffer area around the point, using the
``Vect_point_buffer2`` C function.
:param dist: the distance around the point
:type dist: num
:param dist_x: the distance along x
:type dist_x: num
:param dist_y: the distance along y
:type dist_y: num
:param angle: the angle between 0x and major axis
:type angle: num
:param round_: to make corners round
:type round_: bool
:param tol: fix the maximum distance between theoretical arc and
output segments
:type tol: float
:returns: the buffer as Area object
>>> pnt = Point(0, 0)
>>> boundary, centroid = pnt.buffer(10)
>>> boundary #doctest: +ELLIPSIS
Line([Point(10.000000, 0.000000),...Point(10.000000, 0.000000)])
>>> centroid
Point(0.000000, 0.000000)
"""
if dist is not None:
dist_x = dist
dist_y = dist
elif not dist_x or not dist_y:
raise TypeError("TypeError: buffer expected 1 arguments, got 0")
bound = Line()
p_points = ctypes.pointer(bound.c_points)
libvect.Vect_point_buffer2(
self.x, self.y, dist_x, dist_y, angle, int(round_), tol, p_points
)
return (bound, self)
[docs]class Line(Geo):
"""Instantiate a new Line with a list of tuple, or with a list of Point. ::
>>> line = Line([(0, 0), (1, 1), (2, 0), (1, -1)])
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000),
Point(1.000000, 1.000000),
Point(2.000000, 0.000000),
Point(1.000000, -1.000000)])
..
"""
# geometry type
gtype = libvect.GV_LINE
def __init__(self, points=None, **kargs):
super(Line, self).__init__(**kargs)
if points is not None:
for pnt in points:
self.append(pnt)
def __getitem__(self, key):
"""Get line point of given index, slice allowed. ::
>>> line = Line([(0, 0), (1, 1), (2, 2), (3, 3)])
>>> line[1]
Point(1.000000, 1.000000)
>>> line[-1]
Point(3.000000, 3.000000)
>>> line[:2]
[Point(0.000000, 0.000000), Point(1.000000, 1.000000)]
..
"""
# TODO:
# line[0].x = 10 is not working
# pnt.c_px = ctypes.pointer(self.c_points.contents.x[indx])
# pnt.c_px = ctypes.cast(id(self.c_points.contents.x[indx]),
# ctypes.POINTER(ctypes.c_double))
if isinstance(key, slice):
# import pdb; pdb.set_trace()
# Get the start, stop, and step from the slice
return [
Point(
self.c_points.contents.x[indx],
self.c_points.contents.y[indx],
None if self.is2D else self.c_points.contents.z[indx],
)
for indx in range(*key.indices(len(self)))
]
elif isinstance(key, int):
if key < 0: # Handle negative indices
key += self.c_points.contents.n_points
if key >= self.c_points.contents.n_points:
raise IndexError("Index out of range")
return Point(
self.c_points.contents.x[key],
self.c_points.contents.y[key],
None if self.is2D else self.c_points.contents.z[key],
)
else:
raise ValueError("Invalid argument type: %r." % key)
def __setitem__(self, indx, pnt):
"""Change the coordinate of point. ::
>>> line = Line([(0, 0), (1, 1)])
>>> line[0] = (2, 2)
>>> line
Line([Point(2.000000, 2.000000), Point(1.000000, 1.000000)])
..
"""
x, y, z = get_xyz(pnt)
self.c_points.contents.x[indx] = x
self.c_points.contents.y[indx] = y
self.c_points.contents.z[indx] = z
def __iter__(self):
"""Return a Point generator of the Line"""
return (self.__getitem__(i) for i in range(self.__len__()))
def __len__(self):
"""Return the number of points of the line."""
return self.c_points.contents.n_points
def __str__(self):
return self.to_wkt()
def __repr__(self):
return "Line([%s])" % ", ".join([repr(pnt) for pnt in self.__iter__()])
[docs] def point_on_line(self, distance, angle=0, slope=0):
"""Return a Point object on line in the specified distance, using the
`Vect_point_on_line` C function.
Raise a ValueError If the distance exceed the Line length. ::
>>> line = Line([(0, 0), (1, 1)])
>>> line.point_on_line(5) #doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
Traceback (most recent call last):
...
ValueError: The distance exceed the length of the line,
that is: 1.414214
>>> line.point_on_line(1)
Point(0.707107, 0.707107)
..
"""
# instantiate an empty Point object
maxdist = self.length()
if distance > maxdist:
str_err = "The distance exceed the length of the line, that is: %f"
raise ValueError(str_err % maxdist)
pnt = Point(0, 0, -9999)
if not libvect.Vect_point_on_line(
self.c_points,
distance,
pnt.c_points.contents.x,
pnt.c_points.contents.y,
pnt.c_points.contents.z,
ctypes.pointer(ctypes.c_double(angle)),
ctypes.pointer(ctypes.c_double(slope)),
):
raise ValueError("Vect_point_on_line give an error.")
pnt.is2D = self.is2D
return pnt
[docs] @mapinfo_must_be_set
def alive(self):
"""Return True if this line is alive or False if this line is
dead or its index is out of range.
"""
return bool(libvect.Vect_line_alive(self.c_mapinfo, self.id))
[docs] def append(self, pnt):
"""Appends one point to the end of a line, using the
``Vect_append_point`` C function.
:param pnt: the point to add to line
:type pnt: a Point object or a tuple with the coordinates
>>> line = Line()
>>> line.append((10, 100))
>>> line
Line([Point(10.000000, 100.000000)])
>>> line.append((20, 200))
>>> line
Line([Point(10.000000, 100.000000), Point(20.000000, 200.000000)])
Like python list.
"""
x, y, z = get_xyz(pnt)
libvect.Vect_append_point(self.c_points, x, y, z)
[docs] def bbox(self, bbox=None):
"""Return the bounding box of the line, using ``Vect_line_box``
C function. ::
>>> line = Line([(0, 0), (0, 1), (2, 1), (2, 0)])
>>> bbox = line.bbox()
>>> bbox
Bbox(1.0, 0.0, 2.0, 0.0)
..
"""
bbox = bbox if bbox else Bbox()
libvect.Vect_line_box(self.c_points, bbox.c_bbox)
return bbox
[docs] def extend(self, line, forward=True):
"""Appends points to the end of a line.
:param line: it is possible to extend a line, give a list of points,
or directly with a line_pnts struct.
:type line: Line object of list of points
:param forward: if forward is True the line is extend forward otherwise
is extend backward. The method use the
`Vect_append_points` C function.
:type forward: bool
>>> line = Line([(0, 0), (1, 1)])
>>> line.extend( Line([(2, 2), (3, 3)]) )
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000),
Point(1.000000, 1.000000),
Point(2.000000, 2.000000),
Point(3.000000, 3.000000)])
"""
# set direction
if forward:
direction = libvect.GV_FORWARD
else:
direction = libvect.GV_BACKWARD
# check if is a Line object
if isinstance(line, Line):
c_points = line.c_points
else:
# instantiate a Line object
lin = Line()
for pnt in line:
# add the points to the line
lin.append(pnt)
c_points = lin.c_points
libvect.Vect_append_points(self.c_points, c_points, direction)
[docs] def insert(self, indx, pnt):
"""Insert new point at index position and move all old points at
that position and above up, using ``Vect_line_insert_point``
C function.
:param indx: the index where add new point
:type indx: int
:param pnt: the point to add
:type pnt: a Point object
>>> line = Line([(0, 0), (1, 1)])
>>> line.insert(0, Point(1.000000, -1.000000) )
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(1.000000, -1.000000),
Point(0.000000, 0.000000),
Point(1.000000, 1.000000)])
"""
if indx < 0: # Handle negative indices
indx += self.c_points.contents.n_points
if indx >= self.c_points.contents.n_points:
raise IndexError("Index out of range")
x, y, z = get_xyz(pnt)
libvect.Vect_line_insert_point(self.c_points, indx, x, y, z)
[docs] def length(self):
"""Calculate line length, 3D-length in case of 3D vector line, using
`Vect_line_length` C function. ::
>>> line = Line([(0, 0), (1, 1), (0, 1)])
>>> line.length()
2.414213562373095
..
"""
return libvect.Vect_line_length(self.c_points)
[docs] def length_geodesic(self):
"""Calculate line length, using `Vect_line_geodesic_length` C function.
::
>>> line = Line([(0, 0), (1, 1), (0, 1)])
>>> line.length_geodesic()
2.414213562373095
..
"""
return libvect.Vect_line_geodesic_length(self.c_points)
[docs] def distance(self, pnt):
"""Calculate the distance between line and a point.
:param pnt: the point to calculate distance
:type pnt: a Point object or a tuple with the coordinates
Return a namedtuple with:
* point: the closest point on the line,
* dist: the distance between these two points,
* spdist: distance to point on line from segment beginning
* sldist: distance to point on line form line beginning along line
The distance is compute using the ``Vect_line_distance`` C function.
>>> point = Point(2.3, 0.5)
>>> line = Line([(0, 0), (2, 0), (3, 0)])
>>> line.distance(point) #doctest: +NORMALIZE_WHITESPACE
LineDist(point=Point(2.300000, 0.000000),
dist=0.5, spdist=0.2999999999999998, sldist=2.3)
"""
# instantite outputs
cx = ctypes.c_double(0)
cy = ctypes.c_double(0)
cz = ctypes.c_double(0)
dist = ctypes.c_double(0)
sp_dist = ctypes.c_double(0)
lp_dist = ctypes.c_double(0)
libvect.Vect_line_distance(
self.c_points,
pnt.x,
pnt.y,
0 if pnt.is2D else pnt.z,
0 if self.is2D else 1,
ctypes.byref(cx),
ctypes.byref(cy),
ctypes.byref(cz),
ctypes.byref(dist),
ctypes.byref(sp_dist),
ctypes.byref(lp_dist),
)
# instantiate the Point class
point = Point(cx.value, cy.value, cz.value)
point.is2D = self.is2D
return LineDist(point, dist.value, sp_dist.value, lp_dist.value)
[docs] @mapinfo_must_be_set
def first_cat(self):
"""Fetches FIRST category number for given vector line and field, using
the ``Vect_get_line_cat`` C function.
.. warning::
Not implemented yet.
"""
# TODO: add this method.
# libvect.Vect_get_line_cat(self.c_mapinfo, self.id, self.field)
pass
[docs] def pop(self, indx):
"""Return the point in the index position and remove from the Line.
:param indx: the index where add new point
:type indx: int
>>> line = Line([(0, 0), (1, 1), (2, 2)])
>>> midle_pnt = line.pop(1)
>>> midle_pnt #doctest: +NORMALIZE_WHITESPACE
Point(1.000000, 1.000000)
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000), Point(2.000000, 2.000000)])
"""
if indx < 0: # Handle negative indices
indx += self.c_points.contents.n_points
if indx >= self.c_points.contents.n_points:
raise IndexError("Index out of range")
pnt = self.__getitem__(indx)
libvect.Vect_line_delete_point(self.c_points, indx)
return pnt
[docs] def delete(self, indx):
"""Remove the point in the index position.
:param indx: the index where add new point
:type indx: int
>>> line = Line([(0, 0), (1, 1), (2, 2)])
>>> line.delete(-1)
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000), Point(1.000000, 1.000000)])
"""
if indx < 0: # Handle negative indices
indx += self.c_points.contents.n_points
if indx >= self.c_points.contents.n_points:
raise IndexError("Index out of range")
libvect.Vect_line_delete_point(self.c_points, indx)
[docs] def prune(self):
"""Remove duplicate points, i.e. zero length segments, using
`Vect_line_prune` C function. ::
>>> line = Line([(0, 0), (1, 1), (1, 1), (2, 2)])
>>> line.prune()
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000),
Point(1.000000, 1.000000),
Point(2.000000, 2.000000)])
..
"""
libvect.Vect_line_prune(self.c_points)
[docs] def prune_thresh(self, threshold):
"""Remove points in threshold, using the ``Vect_line_prune_thresh``
C function.
:param threshold: the threshold value where prune points
:type threshold: num
>>> line = Line([(0, 0), (1.0, 1.0), (1.2, 0.9), (2, 2)])
>>> line.prune_thresh(0.5)
>>> line #doctest: +SKIP +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000),
Point(1.000000, 1.000000),
Point(2.000000, 2.000000)])
.. warning ::
prune_thresh is not working yet.
"""
libvect.Vect_line_prune(self.c_points, ctypes.c_double(threshold))
[docs] def remove(self, pnt):
"""Delete point at given index and move all points above down, using
`Vect_line_delete_point` C function.
:param pnt: the point to remove
:type pnt: a Point object or a tuple with the coordinates
>>> line = Line([(0, 0), (1, 1), (2, 2)])
>>> line.remove((2, 2))
>>> line[-1] #doctest: +NORMALIZE_WHITESPACE
Point(1.000000, 1.000000)
..
"""
for indx, point in enumerate(self.__iter__()):
if pnt == point:
libvect.Vect_line_delete_point(self.c_points, indx)
return
raise ValueError("list.remove(x): x not in list")
[docs] def reverse(self):
"""Reverse the order of vertices, using `Vect_line_reverse`
C function. ::
>>> line = Line([(0, 0), (1, 1), (2, 2)])
>>> line.reverse()
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(2.000000, 2.000000),
Point(1.000000, 1.000000),
Point(0.000000, 0.000000)])
..
"""
libvect.Vect_line_reverse(self.c_points)
[docs] def segment(self, start, end):
"""Create line segment. using the ``Vect_line_segment`` C function.
:param start: distance from the beginning of the line where
the segment start
:type start: float
:param end: distance from the beginning of the line where
the segment end
:type end: float
::
# x (1, 1)
# |
# |-
# |
# x--------x (1, 0)
# (0, 0) ^
>>> line = Line([(0, 0), (1, 0), (1, 1)])
>>> line.segment(0.5, 1.5) #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.500000, 0.000000),
Point(1.000000, 0.000000),
Point(1.000000, 0.500000)])
"""
line = Line()
libvect.Vect_line_segment(self.c_points, start, end, line.c_points)
return line
[docs] def to_list(self):
"""Return a list of tuple. ::
>>> line = Line([(0, 0), (1, 1), (2, 0), (1, -1)])
>>> line.to_list()
[(0.0, 0.0), (1.0, 1.0), (2.0, 0.0), (1.0, -1.0)]
..
"""
return [pnt.coords() for pnt in self.__iter__()]
[docs] def to_array(self):
"""Return an array of coordinates. ::
>>> line = Line([(0, 0), (1, 1), (2, 0), (1, -1)])
>>> line.to_array() #doctest: +NORMALIZE_WHITESPACE
array([[ 0., 0.],
[ 1., 1.],
[ 2., 0.],
[ 1., -1.]])
..
"""
return np.array(self.to_list())
[docs] def to_wkt_p(self):
"""Return a Well Known Text string of the line. ::
>>> line = Line([(0, 0), (1, 1), (1, 2)])
>>> line.to_wkt_p() #doctest: +ELLIPSIS
'LINESTRING(0.000000 0.000000, ..., 1.000000 2.000000)'
..
"""
return "LINESTRING(%s)" % ", ".join(
[
" ".join(["%f" % coord for coord in pnt.coords()])
for pnt in self.__iter__()
]
)
[docs] def from_wkt(self, wkt):
"""Create a line reading a WKT string.
:param wkt: the WKT string containing the LINESTRING
:type wkt: str
>>> line = Line()
>>> line.from_wkt("LINESTRING(0 0,1 1,1 2)")
>>> line #doctest: +NORMALIZE_WHITESPACE
Line([Point(0.000000, 0.000000),
Point(1.000000, 1.000000),
Point(1.000000, 2.000000)])
..
"""
match = re.match("LINESTRING\((.*)\)", wkt)
if match:
self.reset()
for coord in match.groups()[0].strip().split(","):
self.append(tuple([float(e) for e in coord.split(" ")]))
else:
return None
[docs] def buffer(
self,
dist=None,
dist_x=None,
dist_y=None,
angle=0,
round_=True,
caps=True,
tol=0.1,
):
"""Return the buffer area around the line, using the
``Vect_line_buffer2`` C function.
:param dist: the distance around the line
:type dist: num
:param dist_x: the distance along x
:type dist_x: num
:param dist_y: the distance along y
:type dist_y: num
:param angle: the angle between 0x and major axis
:type angle: num
:param round_: to make corners round
:type round_: bool
:param tol: fix the maximum distance between theoretical arc and
output segments
:type tol: float
:returns: the buffer as Area object
>>> line = Line([(0, 0), (0, 2)])
>>> boundary, centroid, isles = line.buffer(10)
>>> boundary #doctest: +ELLIPSIS
Line([Point(-10.000000, 0.000000),...Point(-10.000000, 0.000000)])
>>> centroid #doctest: +NORMALIZE_WHITESPACE
Point(0.000000, 0.000000)
>>> isles
[]
..
"""
if dist is not None:
dist_x = dist
dist_y = dist
elif not dist_x or not dist_y:
raise TypeError("TypeError: buffer expected 1 arguments, got 0")
p_bound = ctypes.pointer(ctypes.pointer(libvect.line_pnts()))
pp_isle = ctypes.pointer(ctypes.pointer(ctypes.pointer(libvect.line_pnts())))
n_isles = ctypes.pointer(ctypes.c_int())
libvect.Vect_line_buffer2(
self.c_points,
dist_x,
dist_y,
angle,
int(round_),
int(caps),
tol,
p_bound,
pp_isle,
n_isles,
)
boundary = Line(c_points=p_bound.contents)
isles = [
Line(c_points=pp_isle[i].contents)
for i in range(n_isles.contents.value)
if pp_isle[i]
]
return (boundary, self[0], isles)
[docs] def reset(self):
"""Reset line, using `Vect_reset_line` C function. ::
>>> line = Line([(0, 0), (1, 1), (2, 0), (1, -1)])
>>> len(line)
4
>>> line.reset()
>>> len(line)
0
>>> line
Line([])
..
"""
libvect.Vect_reset_line(self.c_points)
[docs] @mapinfo_must_be_set
def nodes(self):
"""Return the start and end nodes of the line
This method requires topology build.
return: A tuple of Node objects that represent the
start and end point of this line.
"""
if self.has_topology():
n1 = ctypes.c_int()
n2 = ctypes.c_int()
libvect.Vect_get_line_nodes(
self.c_mapinfo, self.id, ctypes.byref(n1), ctypes.byref(n2)
)
return (Node(n1.value, self.c_mapinfo), Node(n2.value, self.c_mapinfo))
[docs]class Node(object):
"""Node class for topological analysis of line neighbors.
Objects of this class will be returned by the node() function
of a Line object.
All methods in this class require a proper setup of the Node
objects. Hence, the correct id and a valid pointer to a mapinfo
object must be provided in the constructions. Otherwise a segfault
may happen.
"""
def __init__(self, v_id, c_mapinfo, **kwords):
"""Construct a Node object
param v_id: The unique node id
param c_mapinfo: A valid pointer to the mapinfo object
param **kwords: Ignored
"""
self.id = v_id # vector id
self.c_mapinfo = c_mapinfo
self._setup()
@mapinfo_must_be_set
def _setup(self):
self.is2D = bool(libvect.Vect_is_3d(self.c_mapinfo) != 1)
self.nlines = libvect.Vect_get_node_n_lines(self.c_mapinfo, self.id)
def __len__(self):
return self.nlines
def __iter__(self):
return self.ilines()
def __repr__(self):
return "Node(%d)" % self.id
[docs] @mapinfo_must_be_set
def alive(self):
"""Return True if this node is alive or False if this node is
dead or its index is out of range.
"""
return bool(libvect.Vect_node_alive(self.c_mapinfo, self.id))
[docs] @mapinfo_must_be_set
def coords(self):
"""Return a tuple with the node coordinates."""
x = ctypes.c_double()
y = ctypes.c_double()
z = ctypes.c_double()
libvect.Vect_get_node_coor(
self.c_mapinfo, self.id, ctypes.byref(x), ctypes.byref(y), ctypes.byref(z)
)
return (x.value, y.value) if self.is2D else (x.value, y.value, z.value)
[docs] def to_wkt(self):
"""Return a "well know text" (WKT) geometry string. ::"""
return "POINT(%s)" % " ".join(["%f" % coord for coord in self.coords()])
[docs] def to_wkb(self):
"""Return a "well know binary" (WKB) geometry array. ::
TODO: Must be implemented
"""
raise Exception("Not implemented")
[docs] def ilines(self, only_in=False, only_out=False):
"""Return a generator with all lines id connected to a node.
The line id is negative if line is ending on the node and positive if
starting from the node.
:param only_in: Return only the lines that are ending in the node
:type only_in: bool
:param only_out: Return only the lines that are starting in the node
:type only_out: bool
"""
for iline in range(self.nlines):
lid = libvect.Vect_get_node_line(self.c_mapinfo, self.id, iline)
if (not only_in and lid > 0) or (not only_out and lid < 0):
yield lid
[docs] @mapinfo_must_be_set
def lines(self, only_in=False, only_out=False):
"""Return a generator with all lines connected to a node.
:param only_in: Return only the lines that are ending in the node
:type only_in: bool
:param only_out: Return only the lines that are starting in the node
:type only_out: bool
"""
for iline in self.ilines(only_in, only_out):
yield Line(v_id=abs(iline), c_mapinfo=self.c_mapinfo)
[docs] @mapinfo_must_be_set
def angles(self):
"""Return a generator with all lines angles in a node."""
for iline in range(self.nlines):
yield libvect.Vect_get_node_line_angle(self.c_mapinfo, self.id, iline)
[docs]class Boundary(Line):
# geometry type
gtype = libvect.GV_BOUNDARY
def __init__(self, **kargs):
super(Boundary, self).__init__(**kargs)
v_id = kargs.get("v_id", 0)
# not sure what it means that v_id is None
v_id = 0 if v_id is None else v_id
self.dir = libvect.GV_FORWARD if v_id > 0 else libvect.GV_BACKWARD
self.c_left = ctypes.pointer(ctypes.c_int())
self.c_right = ctypes.pointer(ctypes.c_int())
@property
def left_area_id(self):
"""Left side area id, only available after read_area_ids() was called"""
return self.c_left.contents.value
@property
def right_area_id(self):
"""Right side area id, only available after read_area_ids() was called"""
return self.c_right.contents.value
def __repr__(self):
return "Boundary([%s])" % ", ".join([repr(pnt) for pnt in self.__iter__()])
@mapinfo_must_be_set
def _centroid(self, side, idonly=False):
if side > 0:
v_id = libvect.Vect_get_area_centroid(self.c_mapinfo, side)
v_id = v_id if v_id else None
if idonly:
return v_id
else:
cntr = Centroid(v_id=v_id, c_mapinfo=self.c_mapinfo)
return cntr
[docs] def left_centroid(self, idonly=False):
"""Return left centroid
:param idonly: True to return only the cat of feature
:type idonly: bool
"""
return self._centroid(self.c_left.contents.value, idonly)
[docs] def right_centroid(self, idonly=False):
"""Return right centroid
:param idonly: True to return only the cat of feature
:type idonly: bool
"""
return self._centroid(self.c_right.contents.value, idonly)
[docs] @mapinfo_must_be_set
def read_area_ids(self):
"""Read and return left and right area ids of the boundary"""
libvect.Vect_get_line_areas(self.c_mapinfo, self.id, self.c_left, self.c_right)
return self.c_left.contents.value, self.c_right.contents.value
[docs] def area(self):
"""Return the area of the polygon.
>>> bound = Boundary(points=[(0, 0), (0, 2), (2, 2), (2, 0),
... (0, 0)])
>>> bound.area()
4.0
"""
libgis.G_begin_polygon_area_calculations()
return libgis.G_area_of_polygon(
self.c_points.contents.x,
self.c_points.contents.y,
self.c_points.contents.n_points,
)
[docs]class Centroid(Point):
"""The Centroid class inherit from the Point class.
Centroid contains an attribute with the C Map_info struct, and attributes
with the id of the Area. ::
>>> centroid = Centroid(x=0, y=10)
>>> centroid
Centroid(0.000000, 10.000000)
>>> from grass.pygrass.vector import VectorTopo
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode='r')
>>> centroid = Centroid(v_id=18, c_mapinfo=test_vect.c_mapinfo)
>>> centroid
Centroid(3.500000, 3.500000)
>>> test_vect.close()
..
"""
# geometry type
gtype = libvect.GV_CENTROID
def __init__(self, area_id=None, **kargs):
super(Centroid, self).__init__(**kargs)
self.area_id = area_id
if self.id and self.c_mapinfo and self.area_id is None:
self.area_id = self._area_id()
elif self.c_mapinfo and self.area_id and self.id is None:
self.id = self._centroid_id()
if self.area_id is not None:
self.read()
# self.c_pline = ctypes.pointer(libvect.P_line()) if topology else None
def __repr__(self):
return "Centroid(%s)" % ", ".join(["%f" % co for co in self.coords()])
@mapinfo_must_be_set
def _centroid_id(self):
"""Return the centroid_id, using the c_mapinfo and an area_id
attributes of the class, and calling the Vect_get_area_centroid
C function, if no centroid_id were found return None"""
centroid_id = libvect.Vect_get_area_centroid(self.c_mapinfo, self.area_id)
return centroid_id if centroid_id != 0 else None
@mapinfo_must_be_set
def _area_id(self):
"""Return the area_id, using the c_mapinfo and an centroid_id
attributes of the class, and calling the Vect_centroid_area
C function, if no area_id were found return None"""
area_id = libvect.Vect_get_centroid_area(self.c_mapinfo, self.id)
return area_id if area_id != 0 else None
[docs]class Isle(Geo):
"""An Isle is an area contained by another area."""
def __init__(self, **kargs):
super(Isle, self).__init__(**kargs)
# self.area_id = area_id
def __repr__(self):
return "Isle(%d)" % (self.id)
[docs] @mapinfo_must_be_set
def boundaries(self):
"""Return a list of boundaries"""
ilist = Ilist()
libvect.Vect_get_isle_boundaries(self.c_mapinfo, self.id, ilist.c_ilist)
return ilist
[docs] @mapinfo_must_be_set
def bbox(self, bbox=None):
"""Return bounding box of Isle"""
bbox = bbox if bbox else Bbox()
libvect.Vect_get_isle_box(self.c_mapinfo, self.id, bbox.c_bbox)
return bbox
[docs] @mapinfo_must_be_set
def points(self):
"""Return a Line object with the outer ring points"""
line = Line()
libvect.Vect_get_isle_points(self.c_mapinfo, self.id, line.c_points)
return line
[docs] def to_wkt(self):
"""Return a Well Known Text string of the isle. ::
For now the outer ring is returned
TODO: Implement inner rings detected from isles
"""
line = self.points()
return "Polygon((%s))" % ", ".join(
[" ".join(["%f" % coord for coord in pnt]) for pnt in line.to_list()]
)
[docs] def to_wkb(self):
"""Return a "well know text" (WKB) geometry array. ::"""
raise Exception("Not implemented")
[docs] @mapinfo_must_be_set
def points_geos(self):
"""Return a Line object with the outer ring points"""
return libvect.Vect_get_isle_points_geos(self.c_mapinfo, self.id)
[docs] @mapinfo_must_be_set
def area_id(self):
"""Returns area id for isle."""
return libvect.Vect_get_isle_area(self.c_mapinfo, self.id)
[docs] @mapinfo_must_be_set
def alive(self):
"""Check if isle is alive or dead (topology required)"""
return bool(libvect.Vect_isle_alive(self.c_mapinfo, self.id))
[docs] @mapinfo_must_be_set
def contain_pnt(self, pnt):
"""Check if point is in area.
:param pnt: the point to remove
:type pnt: a Point object or a tuple with the coordinates
"""
bbox = self.bbox()
return bool(
libvect.Vect_point_in_island(
pnt.x, pnt.y, self.c_mapinfo, self.id, bbox.c_bbox.contents
)
)
[docs] def area(self):
"""Return the area value of an Isle"""
border = self.points()
return libgis.G_area_of_polygon(
border.c_points.contents.x,
border.c_points.contents.y,
border.c_points.contents.n_points,
)
[docs] def perimeter(self):
"""Return the perimeter value of an Isle."""
border = self.points()
return libvect.Vect_line_geodesic_length(border.c_points)
[docs]class Isles(object):
def __init__(self, c_mapinfo, area_id=None):
self.c_mapinfo = c_mapinfo
self.area_id = area_id
self._isles_id = None
self._isles = None
if area_id:
self._isles_id = self.isles_ids()
self._isles = self.isles()
@mapinfo_must_be_set
def __len__(self):
return libvect.Vect_get_area_num_isles(self.c_mapinfo, self.area_id)
def __repr__(self):
return "Isles(%r)" % self.area_id
def __getitem__(self, key):
if self._isles is None:
self.isles()
return self._isles[key]
[docs] @mapinfo_must_be_set
def isles_ids(self):
"""Return the id of isles"""
return [
libvect.Vect_get_area_isle(self.c_mapinfo, self.area_id, i)
for i in range(self.__len__())
]
[docs] @mapinfo_must_be_set
def isles(self):
"""Return isles"""
return [
Isle(v_id=isle_id, c_mapinfo=self.c_mapinfo) for isle_id in self._isles_id
]
[docs]class Area(Geo):
"""
Vect_build_line_area,
Vect_find_area,
Vect_get_area_box,
Vect_get_area_points_geos,
Vect_centroid_area,
Vect_get_isle_area,
Vect_get_line_areas,
Vect_get_num_areas,
Vect_get_point_in_area,
Vect_isle_find_area,
Vect_point_in_area,
Vect_point_in_area_outer_ring,
Vect_read_area_geos,
Vect_remove_small_areas,
Vect_select_areas_by_box,
Vect_select_areas_by_polygon
"""
# geometry type
gtype = libvect.GV_AREA
def __init__(self, **kargs):
super(Area, self).__init__(**kargs)
# set the attributes
# if self.attrs and self.cat:
# self.attrs.cat = self.cat
def __repr__(self):
return "Area(%d)" % self.id if self.id else "Area( )"
@property
def cat(self):
centroid = self.centroid()
return centroid.cat if centroid else None
[docs] @mapinfo_must_be_set
def points(self, line=None):
"""Return a Line object with the outer ring
:param line: a Line object to fill with info from points of area
:type line: a Line object
"""
line = Line() if line is None else line
libvect.Vect_get_area_points(self.c_mapinfo, self.id, line.c_points)
return line
[docs] @mapinfo_must_be_set
def centroid(self):
"""Return the centroid
:param centroid: a Centroid object to fill with info from centroid of area
:type centroid: a Centroid object
"""
centroid_id = libvect.Vect_get_area_centroid(self.c_mapinfo, self.id)
if centroid_id:
return Centroid(v_id=centroid_id, c_mapinfo=self.c_mapinfo, area_id=self.id)
[docs] @mapinfo_must_be_set
def num_isles(self):
return libvect.Vect_get_area_num_isles(self.c_mapinfo, self.id)
[docs] @mapinfo_must_be_set
def isles(self, isles=None):
"""Return a list of islands located in this area"""
if isles is not None:
isles.area_id = self.id
return isles
return Isles(self.c_mapinfo, self.id)
[docs] @mapinfo_must_be_set
def area(self):
"""Returns area of area without areas of isles.
double Vect_get_area_area (const struct Map_info \*Map, int area)
"""
return libvect.Vect_get_area_area(self.c_mapinfo, self.id)
[docs] @mapinfo_must_be_set
def alive(self):
"""Check if area is alive or dead (topology required)"""
return bool(libvect.Vect_area_alive(self.c_mapinfo, self.id))
[docs] @mapinfo_must_be_set
def bbox(self, bbox=None):
"""Return the Bbox of area
:param bbox: a Bbox object to fill with info from bounding box of area
:type bbox: a Bbox object
"""
bbox = bbox if bbox else Bbox()
libvect.Vect_get_area_box(self.c_mapinfo, self.id, bbox.c_bbox)
return bbox
[docs] @mapinfo_must_be_set
def buffer(
self,
dist=None,
dist_x=None,
dist_y=None,
angle=0,
round_=True,
caps=True,
tol=0.1,
):
"""Return the buffer area around the area, using the
``Vect_area_buffer2`` C function.
:param dist: the distance around the area
:type dist: num
:param dist_x: the distance along x
:type dist_x: num
:param dist_y: the distance along y
:type dist_y: num
:param angle: the angle between 0x and major axis
:type angle: num
:param round_: to make corners round
:type round_: bool
:param tol: fix the maximum distance between theoretical arc and
output segments
:type tol: float
:returns: the buffer as line, centroid, isles object tuple
"""
if dist is not None:
dist_x = dist
dist_y = dist
elif not dist_x or not dist_y:
raise TypeError("TypeError: buffer expected 1 arguments, got 0")
p_bound = ctypes.pointer(ctypes.pointer(libvect.line_pnts()))
pp_isle = ctypes.pointer(ctypes.pointer(ctypes.pointer(libvect.line_pnts())))
n_isles = ctypes.pointer(ctypes.c_int())
libvect.Vect_area_buffer2(
self.c_mapinfo,
self.id,
dist_x,
dist_y,
angle,
int(round_),
int(caps),
tol,
p_bound,
pp_isle,
n_isles,
)
return (
Line(c_points=p_bound.contents),
self.centroid(),
[Line(c_points=pp_isle[i].contents) for i in range(n_isles.contents.value)],
)
[docs] @mapinfo_must_be_set
def boundaries(self, ilist=False):
"""Creates list of boundaries for given area.
int Vect_get_area_boundaries(const struct Map_info \*Map,
int area, struct ilist \*List)
"""
ilst = Ilist()
libvect.Vect_get_area_boundaries(self.c_mapinfo, self.id, ilst.c_ilist)
if ilist:
return ilist
return [Boundary(v_id=abs(v_id), c_mapinfo=self.c_mapinfo) for v_id in ilst]
[docs] def to_wkt(self):
"""Return a "well know text" (WKT) area string, this method uses
the GEOS implementation in the vector library. ::
"""
return decode(libvect.Vect_read_area_to_wkt(self.c_mapinfo, self.id))
[docs] def to_wkb(self):
"""Return a "well know binary" (WKB) area byte array, this method uses
the GEOS implementation in the vector library. ::
"""
size = ctypes.c_size_t()
barray = libvect.Vect_read_area_to_wkb(
self.c_mapinfo, self.id, ctypes.byref(size)
)
return ctypes.string_at(barray, size.value)
[docs] @mapinfo_must_be_set
def cats(self, cats=None):
"""Get area categories.
:param cats: a Cats object to fill with info with area categories
:type cats: a Cats object
"""
cats = cats if cats else Cats()
libvect.Vect_get_area_cats(self.c_mapinfo, self.id, cats.c_cats)
return cats
[docs] def get_first_cat(self):
"""Find FIRST category of given field and area.
int Vect_get_area_cat(const struct Map_info \*Map, int area, int field)
..warning: Not implemented
"""
pass
[docs] @mapinfo_must_be_set
def contains_point(self, point, bbox=None):
"""Check if point is in area.
:param point: the point to analyze
:type point: a Point object or a tuple with the coordinates
:param bbox: the bounding box where run the analysis
:type bbox: a Bbox object
"""
bbox = bbox if bbox else self.bbox()
return bool(
libvect.Vect_point_in_area(
point.x, point.y, self.c_mapinfo, self.id, bbox.c_bbox
)
)
[docs] @mapinfo_must_be_set
def perimeter(self):
"""Calculate area perimeter.
:return: double Vect_area_perimeter (const struct line_pnts \*Points)
"""
border = self.points()
return libvect.Vect_line_geodesic_length(border.c_points)
#
# Define a dictionary to convert the feature type to name and or object
#
GV_TYPE = {
libvect.GV_POINT: {"label": "point", "obj": Point},
libvect.GV_LINE: {"label": "line", "obj": Line},
libvect.GV_BOUNDARY: {"label": "boundary", "obj": Boundary},
libvect.GV_CENTROID: {"label": "centroid", "obj": Centroid},
libvect.GV_FACE: {"label": "face", "obj": None},
libvect.GV_KERNEL: {"label": "kernel", "obj": None},
libvect.GV_AREA: {"label": "area", "obj": Area},
libvect.GV_VOLUME: {"label": "volume", "obj": None},
}
GEOOBJ = {
"areas": Area,
"dblinks": None,
"faces": None,
"holes": None,
"boundaries": Boundary,
"islands": Isle,
"kernels": None,
"line_points": None,
"points": Point,
"lines": Line,
"nodes": Node,
"volumes": None,
}
[docs]def c_read_next_line(c_mapinfo, c_points, c_cats):
v_id = c_mapinfo.contents.next_line
v_id = v_id if v_id != 0 else None
ftype = libvect.Vect_read_next_line(c_mapinfo, c_points, c_cats)
if ftype == -2:
raise StopIteration()
if ftype == -1:
raise
return ftype, v_id, c_points, c_cats
[docs]def read_next_line(
c_mapinfo, table=None, writeable=False, c_points=None, c_cats=None, is2D=True
):
"""Return the next geometry feature of a vector map."""
# Take care of good memory management
free_points = False
if c_points is None:
free_points = True
free_cats = False
if c_cats is None:
free_cats = True
c_points = c_points if c_points else ctypes.pointer(libvect.line_pnts())
c_cats = c_cats if c_cats else ctypes.pointer(libvect.line_cats())
ftype, v_id, c_points, c_cats = c_read_next_line(c_mapinfo, c_points, c_cats)
return GV_TYPE[ftype]["obj"](
v_id=v_id,
c_mapinfo=c_mapinfo,
c_points=c_points,
c_cats=c_cats,
table=table,
writeable=writeable,
is2D=is2D,
free_points=free_points,
free_cats=free_cats,
)
[docs]def c_read_line(feature_id, c_mapinfo, c_points, c_cats):
nmax = libvect.Vect_get_num_lines(c_mapinfo)
if feature_id < 0: # Handle negative indices
feature_id += nmax + 1
if feature_id > nmax:
raise IndexError("Index out of range")
if feature_id > 0:
ftype = libvect.Vect_read_line(c_mapinfo, c_points, c_cats, feature_id)
return feature_id, ftype, c_points, c_cats
else:
raise ValueError("The index must be >0, %r given." % feature_id)
[docs]def read_line(
feature_id,
c_mapinfo,
table=None,
writeable=False,
c_points=None,
c_cats=None,
is2D=True,
):
"""Return a geometry object given the feature id and the c_mapinfo."""
# Take care of good memory management
free_points = False
if c_points is None:
free_points = True
free_cats = False
if c_cats is None:
free_cats = True
c_points = c_points if c_points else ctypes.pointer(libvect.line_pnts())
c_cats = c_cats if c_cats else ctypes.pointer(libvect.line_cats())
feature_id, ftype, c_points, c_cats = c_read_line(
feature_id, c_mapinfo, c_points, c_cats
)
if GV_TYPE[ftype]["obj"] is not None:
return GV_TYPE[ftype]["obj"](
v_id=feature_id,
c_mapinfo=c_mapinfo,
c_points=c_points,
c_cats=c_cats,
table=table,
writeable=writeable,
is2D=is2D,
free_points=free_points,
free_cats=free_cats,
)
if __name__ == "__main__":
import doctest
from grass.pygrass import utils
utils.create_test_vector_map(test_vector_name)
doctest.testmod()
"""Remove the generated vector map, if exist"""
from grass.pygrass.utils import get_mapset_vector
from grass.script.core import run_command
mset = get_mapset_vector(test_vector_name, mapset="")
if mset:
run_command("g.remove", flags="f", type="vector", name=test_vector_name)
