def test_union_geometry(self):
"""Test union_geometry work"""
# Create big polygons from the point layer,
# then the union is one BIG polygon
dx = dy = 10
points = self._create_points()
polygons = points_to_rectangles(points, dx, dy)
geom = union_geometry(polygons)
# The union is the rectangle
# noinspection PyCallByClass,PyTypeChecker
expected_area = QgsGeometry.fromPolygon([[
QgsPoint(10, 30),
QgsPoint(40, 30),
QgsPoint(40, 0),
QgsPoint(10, 0)]])
self.assertTrue(geom.isGeosValid())
self.assertFalse(geom.isMultipart())
self.assertAlmostEquals(geom.area(), 3 * dx * 3 * dy)
self.assertTrue((geom.isGeosEqual(expected_area)))
polygons = points_to_rectangles(points, 0.5 * dx, 0.5 * dy)
geom = union_geometry(polygons)
# The union is 9 squares
self.assertAlmostEquals(geom.area(), 1.5 * dx * 1.5 * dy)
self.assertTrue(geom.isMultipart())
def test_union_geometry(self):
"""Test union_geometry work"""
# Create big polygons from the point layer,
# then the union is one BIG polygon
dx = dy = 10
points = self._create_points()
polygons = points_to_rectangles(points, dx, dy)
geom = union_geometry(polygons)
# The union is the rectangle
# noinspection PyCallByClass,PyTypeChecker
expected_area = QgsGeometry.fromPolygon([[
QgsPoint(10, 30),
QgsPoint(40, 30),
QgsPoint(40, 0),
QgsPoint(10, 0)
]])
self.assertTrue(geom.isGeosValid())
self.assertFalse(geom.isMultipart())
self.assertAlmostEquals(geom.area(), 3 * dx * 3 * dy)
self.assertTrue((geom.isGeosEqual(expected_area)))
polygons = points_to_rectangles(points, 0.5 * dx, 0.5 * dy)
geom = union_geometry(polygons)
# The union is 9 squares
self.assertAlmostEquals(geom.area(), 1.5 * dx * 1.5 * dy)
self.assertTrue(geom.isMultipart())
def test_points_to_rectangles(self):
"""Test points_to_rectangles work
"""
points = self._create_points()
x_index = points.dataProvider().fieldNameIndex('X')
y_index = points.dataProvider().fieldNameIndex('Y')
dx, dy = 1, 2
polygons = points_to_rectangles(points, dx, dy)
for feature in polygons.getFeatures():
geom = feature.geometry()
attr = feature.attributes()
self.assertTrue(geom.isGeosValid())
self.assertAlmostEquals(geom.area(), dx * dy)
p = geom.centroid().asPoint()
x, y = [attr[index] for index in [x_index, y_index]]
self.assertLess(abs(p.x() - x), dx)
self.assertLess(abs(p.y() - y), dy)
def test_points_to_rectangles(self):
"""Test points_to_rectangles work
"""
points = self._create_points()
x_index = points.dataProvider().fieldNameIndex('X')
y_index = points.dataProvider().fieldNameIndex('Y')
dx, dy = 1, 2
polygons = points_to_rectangles(points, dx, dy)
for feature in polygons.getFeatures():
geom = feature.geometry()
attr = feature.attributes()
self.assertTrue(geom.isGeosValid())
self.assertAlmostEquals(geom.area(), dx * dy)
p = geom.centroid().asPoint()
x, y = [attr[index] for index in [x_index, y_index]]
self.assertLess(abs(p.x() - x), dx)
self.assertLess(abs(p.y() - y), dy)
