def cat(self, cat_id, vtype, layer=None, generator=False, geo=None):
"""Return the geometry features with category == cat_id.
:param cat_id: the category number
:type cat_id: int
:param vtype: the type of geometry feature that we are looking for
:type vtype: str
:param layer: the layer number that will be used
:type layer: int
:param generator: if True return a generator otherwise it return a
list of features
:type generator: bool
"""
if geo is None and vtype not in _GEOOBJ:
keys = "', '".join(sorted(_GEOOBJ.keys()))
raise ValueError("vtype not supported, use one of: '%s'" % keys)
Obj = _GEOOBJ[vtype] if geo is None else geo
ilist = Ilist()
libvect.Vect_cidx_find_all(self.c_mapinfo,
layer if layer else self.layer,
Obj.gtype, cat_id, ilist.c_ilist)
is2D = not self.is_3D()
if generator:
return (read_line(feature_id=v_id, c_mapinfo=self.c_mapinfo,
table=self.table, writeable=self.writeable,
is2D=is2D)
for v_id in ilist)
else:
return [read_line(feature_id=v_id, c_mapinfo=self.c_mapinfo,
table=self.table, writeable=self.writeable,
is2D=is2D)
for v_id in ilist]
def geos(self, point, maxdist, type='all', exclude=None):
"""Find the nearest line. Vect_find_line_list
Valid type are all the keys in find.vtype dictionary
"""
excl = Ilist(exclude) if exclude else Ilist([])
found = Ilist()
if libvect.Vect_find_line_list(self.c_mapinfo, point.x, point.y,
point.z if point.z else 0,
self.vtype[type], float(maxdist),
int(not point.is2D), excl.c_ilist,
found.c_ilist):
return [
read_line(f_id, self.c_mapinfo, self.table, self.writable)
for f_id in found
]
else:
return []
def nodes(self, bbox):
"""Find the nearest area. Vect_find_area"""
found = Ilist()
if libvect.Vect_select_nodes_by_box(self.c_mapinfo, bbox.c_bbox,
found.c_ilist):
for n_id in found:
yield Node(v_id=n_id,
c_mapinfo=self.c_mapinfo,
table=self.table,
writable=self.writable)
def nodes(self, bbox):
"""Find nodes inside a boundingbox.
:param bbox: The boundingbox to search in
:type bbox: grass.pygrass.vector.basic.Bbox
:return: A list of nodes or None if nothing was found
This methods uses libvect.Vect_select_nodes_by_box()
Examples:
>>> from grass.pygrass.vector import VectorTopo
>>> from grass.pygrass.vector.basic import Bbox
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
# Find nodes in box
>>> bbox = Bbox(north=5, south=-1, east=15, west=9)
>>> result = test_vect.find_by_bbox.nodes(bbox=bbox)
>>> [node for node in result]
[Node(2), Node(1), Node(4), Node(3), Node(5), Node(6)]
>>> bbox = Bbox(north=20, south=18, east=20, west=18)
>>> test_vect.find_by_bbox.nodes(bbox=bbox)
>>> test_vect.close()
"""
found = Ilist()
if libvect.Vect_select_nodes_by_box(self.c_mapinfo, bbox.c_bbox, found.c_ilist):
if len(found) > 0:
return (
Node(
v_id=n_id,
c_mapinfo=self.c_mapinfo,
table=self.table,
writeable=self.writeable,
)
for n_id in found
)
def geos(self, point, maxdist, type="all", exclude=None):
"""Find the nearest vector features around a specific point.
:param point: The point to search
:type point: grass.pygrass.vector.geometry.Point
:param maxdist: The maximum search distance around the point
:type maxdist: float
:param type: The type of feature to search for
Valid type are all the keys in find.vtype dictionary
:type type: string
:param exclude: if > 0 number of lines which should be
excluded from selection
:return: A list of grass.pygrass.vector.geometry
(Line, Point, Boundary, Centroid) if found or None
This methods uses libvect.Vect_find_line_list()()
Examples:
>>> from grass.pygrass.vector import VectorTopo
>>> from grass.pygrass.vector.geometry import Point
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open('r')
# Find multiple features
>>> points = (Point(10,0), Point(10,5), Point(14,2))
>>> result = []
>>> for point in points:
... f = test_vect.find_by_point.geos(point=point,
... maxdist=1.5)
... if f:
... result.append(f)
>>> for f in result:
... print(f) #doctest: +NORMALIZE_WHITESPACE
[Line([Point(10.000000, 4.000000),
Point(10.000000, 2.000000),
Point(10.000000, 0.000000)])]
[Line([Point(10.000000, 4.000000),
Point(10.000000, 2.000000),
Point(10.000000, 0.000000)]),
Point(10.000000, 6.000000)]
[Line([Point(14.000000, 4.000000),
Point(14.000000, 2.000000),
Point(14.000000, 0.000000)])]
# Find multiple boundaries
>>> point = Point(3,3)
>>> result = test_vect.find_by_point.geos(point=Point(3,3),
... type="boundary",
... maxdist=1.5)
>>> result #doctest: +NORMALIZE_WHITESPACE
[Boundary([Point(0.000000, 4.000000), Point(4.000000, 4.000000)]),
Boundary([Point(4.000000, 4.000000), Point(4.000000, 0.000000)]),
Boundary([Point(1.000000, 1.000000), Point(1.000000, 3.000000),
Point(3.000000, 3.000000), Point(3.000000, 1.000000),
Point(1.000000, 1.000000)]),
Boundary([Point(4.000000, 4.000000), Point(6.000000, 4.000000)])]
# Find multiple centroids
>>> point = Point(3,3)
>>> result = test_vect.find_by_point.geos(point=Point(3,3),
... type="centroid",
... maxdist=1.5)
>>> result #doctest: +NORMALIZE_WHITESPACE
[Centroid(2.500000, 2.500000),
Centroid(3.500000, 3.500000)]
>>> test_vect.find_by_point.geos(point=Point(20,20), maxdist=0)
>>> test_vect.close()
"""
excl = Ilist(exclude) if exclude else Ilist([])
found = Ilist()
if libvect.Vect_find_line_list(
self.c_mapinfo,
point.x,
point.y,
point.z if point.z else 0,
self.vtype[type],
float(maxdist),
int(not point.is2D),
excl.c_ilist,
found.c_ilist,
):
return [
read_line(f_id, self.c_mapinfo, self.table, self.writeable)
for f_id in found
]