from shapely.ops import split from . import unittest from shapely.geometry import Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, GeometryCollection from shapely.ops import cascaded_union, linemerge class TestSplitGeometry(unittest.TestCase): # helper class for testing below def helper(self, geom, splitter, expected_chunks): s = split(geom, splitter) self.assertEqual(s.type, "GeometryCollection") self.assertEqual(len(s), expected_chunks) if expected_chunks > 1: # split --> expected collection that when merged is again equal to original geometry if s.geoms[0].type == 'LineString': self.assertTrue(linemerge(s).simplify(0.000001).equals(geom)) elif s.geoms[0].type == 'Polygon': union = cascaded_union(s).simplify(0.000001) self.assertTrue(union.equals(geom)) self.assertEqual(union.area, geom.area) else: raise ValueError elif expected_chunks == 1: # not split --> expected equal to line self.assertTrue(s[0].equals(geom)) def test_split_closed_line_with_point(self): # point at start/end of closed ring -> return equal # see GH #524 ls = LineString([(0,0), (0, 1), (1, 1), (1, 0), (0, 0)]) splitter = Point(0, 0) self.helper(ls, splitter, 1) class TestSplitPolygon(TestSplitGeometry): poly_simple = Polygon([(0, 0), (2, 0), (2, 2), (0, 2), (0, 0)]) poly_hole = Polygon([(0, 0), (2, 0), (2, 2), (0, 2), (0, 0)], [[(0.5, 0.5), (0.5, 1.5), (1.5, 1.5), (1.5, 0.5), (0.5, 0.5)]]) def test_split_poly_with_line(self): # crossing at 2 points --> return 2 segments splitter = LineString([(1, 3), (1, -3)]) self.helper(self.poly_simple, splitter, 2) self.helper(self.poly_hole, splitter, 2) # touching the boundary--> return equal splitter = LineString([(0, 2), (5, 2)]) self.helper(self.poly_simple, splitter, 1) self.helper(self.poly_hole, splitter, 1) # inside the polygon --> return equal splitter = LineString([(0.2, 0.2), (1.7, 1.7), (3, 2)]) self.helper(self.poly_simple, splitter, 1) self.helper(self.poly_hole, splitter, 1) # outside the polygon --> return equal splitter = LineString([(0, 3), (3, 3) , (3, 0)]) self.helper(self.poly_simple, splitter, 1) self.helper(self.poly_hole, splitter, 1) def test_split_poly_with_other(self): with self.assertRaises(ValueError): split(self.poly_simple, Point(1, 1)) with self.assertRaises(ValueError): split(self.poly_simple, MultiPoint([(1, 1), (3, 4)])) with self.assertRaises(ValueError): split(self.poly_simple, self.poly_hole) class TestSplitLine(TestSplitGeometry): ls = LineString([(0, 0), (1.5, 1.5), (3.0, 4.0)]) def test_split_line_with_point(self): # point on line interior --> return 2 segments splitter = Point(1, 1) self.helper(self.ls, splitter, 2) # point on line point --> return 2 segments splitter = Point(1.5, 1.5) self.helper(self.ls, splitter, 2) # point on boundary --> return equal splitter = Point(3, 4) self.helper(self.ls, splitter, 1) # point on exterior of line --> return equal splitter = Point(2, 2) self.helper(self.ls, splitter, 1) def test_split_line_with_multipoint(self): # points on line interior --> return 4 segments splitter = MultiPoint([(1,1), (1.5, 1.5), (0.5, 0.5)]) self.helper(self.ls, splitter, 4) # points on line interior and boundary -> return 2 segments splitter = MultiPoint([(1, 1), (3, 4)]) self.helper(self.ls, splitter, 2) # point on linear interior but twice --> return 2 segments splitter = MultiPoint([(1, 1), (1.5, 1.5), (1, 1)]) self.helper(self.ls, splitter, 3) def test_split_line_with_line(self): # crosses at one point --> return 2 segments splitter = LineString([(0, 1), (1, 0)]) self.helper(self.ls, splitter, 2) # crosses at two points --> return 3 segments splitter = LineString([(0, 1), (1, 0), (1, 2)]) self.helper(self.ls, splitter, 3) # overlaps --> raise splitter = LineString([(0, 0), (15, 15)]) with self.assertRaises(ValueError): self.helper(self.ls, splitter, 1) # does not cross --> return equal splitter = LineString([(0, 1), (0, 2)]) self.helper(self.ls, splitter, 1) # is touching the boundary --> return equal splitter = LineString([(-1, 1), (1, -1)]) self.assertTrue(splitter.touches(self.ls)) self.helper(self.ls, splitter, 1) def test_split_line_with_multiline(self): # crosses at one point --> return 2 segments splitter = MultiLineString([[(0, 1), (1, 0)], [(0, 0), (2, -2)]]) self.helper(self.ls, splitter, 2) # crosses at two points --> return 3 segments splitter = MultiLineString([[(0, 1), (1, 0)], [(0, 2), (2, 0)]]) self.helper(self.ls, splitter, 3) # crosses at three points --> return 4 segments splitter = MultiLineString([[(0, 1), (1, 0)], [(0, 2), (2, 0), (2.2, 3.2)]]) self.helper(self.ls, splitter, 4) # overlaps --> raise splitter = MultiLineString([[(0, 0), (1.5, 1.5)], [(1.5, 1.5), (3, 4)]]) with self.assertRaises(ValueError): self.helper(self.ls, splitter, 1) # does not cross --> return equal splitter = MultiLineString([[(0, 1), (0, 2)], [(1, 0), (2, 0)]]) self.helper(self.ls, splitter, 1) def test_split_line_with_polygon(self): # crosses at two points --> return 3 segments splitter = Polygon([(1, 0), (1, 2), (2, 2), (2, 0), (1, 0)]) self.helper(self.ls, splitter, 3) # crosses at one point and touches boundary --> return 2 segments splitter = Polygon([(0, 0), (1, 2), (2, 2), (1, 0), (0, 0)]) self.helper(self.ls, splitter, 2) # exterior crosses at one point and touches at (0, 0) # interior crosses at two points splitter = Polygon([(0, 0), (2, 0), (2, 2), (0, 2), (0, 0)], [[(0.5, 0.5), (0.5, 1.5), (1.5, 1.5), (1.5, 0.5), (0.5, 0.5)]]) self.helper(self.ls, splitter, 4) def test_split_line_with_multipolygon(self): poly1 = Polygon([(0, 0), (2, 0), (2, 2), (0, 2), (0, 0)]) # crosses at one point and touches at (0, 0) poly2 = Polygon([(0.5, 0.5), (0.5, 1.5), (1.5, 1.5), (1.5, 0.5), (0.5, 0.5)]) # crosses at two points poly3 = Polygon([(0, 0), (0, -2), (-2, -2), (-2, 0), (0, 0)]) # not crossing splitter = MultiPolygon([poly1, poly2, poly3]) self.helper(self.ls, splitter, 4) class TestSplitClosedRing(TestSplitGeometry): ls = LineString([[0, 0], [0, 1], [1, 1], [1, 0], [0, 0]]) def test_split_closed_ring_with_point(self): splitter = Point([0.0, 0.0]) self.helper(self.ls, splitter, 1) splitter = Point([0.0, 0.5]) self.helper(self.ls, splitter, 2) result = split(self.ls, splitter) assert result[0].coords[:] == [(0, 0), (0.0, 0.5)] assert result[1].coords[:] == [(0.0, 0.5), (0, 1), (1, 1), (1, 0), (0, 0)] # previously failed, see GH#585 splitter = Point([0.5, 0.0]) self.helper(self.ls, splitter, 2) result = split(self.ls, splitter) assert result[0].coords[:] == [(0, 0), (0, 1), (1, 1), (1, 0), (0.5, 0)] assert result[1].coords[:] == [(0.5, 0), (0, 0)] splitter = Point([2.0, 2.0]) self.helper(self.ls, splitter, 1) class TestSplitMulti(TestSplitGeometry): def test_split_multiline_with_point(self): # a cross-like multilinestring with a point in the middle --> return 4 line segments l1 = LineString([(0, 1), (2, 1)]) l2 = LineString([(1, 0), (1, 2)]) ml = MultiLineString([l1, l2]) splitter = Point((1, 1)) self.helper(ml, splitter, 4) def test_split_multiline_with_multipoint(self): # a cross-like multilinestring with a point in middle, a point on one of the lines and a point in the exterior # --> return 4+1 line segments l1 = LineString([(0, 1), (3, 1)]) l2 = LineString([(1, 0), (1, 2)]) ml = MultiLineString([l1, l2]) splitter = MultiPoint([(1, 1), (2, 1), (4, 2)]) self.helper(ml, splitter, 5) def test_split_multipolygon_with_line(self): # two polygons with a crossing line --> return 4 triangles poly1 = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)]) poly2 = Polygon([(1, 1), (1, 2), (2, 2), (2, 1), (1, 1)]) mpoly = MultiPolygon([poly1, poly2]) ls = LineString([(-1, -1), (3, 3)]) self.helper(mpoly, ls, 4) # two polygons away from the crossing line --> return identity poly1 = Polygon([(10, 10), (10, 11), (11, 11), (11, 10), (10, 10)]) poly2 = Polygon([(-10, -10), (-10, -11), (-11, -11), (-11, -10), (-10, -10)]) mpoly = MultiPolygon([poly1, poly2]) ls = LineString([(-1, -1), (3, 3)]) self.helper(mpoly, ls, 2)