def polygon_elongation(polygon: QgsPolygon):
'''
Compute the elongation of a rectangle, equals to the ratio length / width.
If the polygon in parameter has a number of coordinates different from 5,
the value -1.0 is returned.
'''
# if len(polygon.vertices()) != 5:
if _geometry_num_vertices(polygon) != 5:
return -1.0
vertices = _geometry_vertices(polygon, 2)
# v0 = QgsPoint(vertices[0])
# v1 = QgsPoint(vertices[1])
# v2 = QgsPoint(vertices[2])
v0 = QgsPoint(vertices[0].x(), vertices[0].y())
v1 = QgsPoint(vertices[1].x(), vertices[1].y())
v2 = QgsPoint(vertices[2].x(), vertices[2].y())
length = v0.distance(v1.x(), v1.y())
length2 = v1.distance(v2.x(), v2.y())
if length == length2:
return length / length2
return lentgh2 / lentgh
def testMeasureLineProjected(self):
# +-+
# | |
# +-+ +
# test setting/getting the source CRS
da_3068 = QgsDistanceArea()
da_wsg84 = QgsDistanceArea()
da_3068.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:3068'))
if (da_3068.sourceCrs().isGeographic()):
da_3068.setEllipsoid(da_3068.sourceCrs().ellipsoidAcronym())
print(("setting [{}] srid [{}] description [{}]".format(u'Soldner Berlin', da_3068.sourceCrs().authid(), da_3068.sourceCrs().description())))
self.assertEqual(da_3068.sourceCrs().authid(), 'EPSG:3068')
da_wsg84.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:4326'))
if (da_wsg84.sourceCrs().isGeographic()):
da_wsg84.setEllipsoid(da_wsg84.sourceCrs().ellipsoidAcronym())
self.assertEqual(da_wsg84.sourceCrs().authid(), 'EPSG:4326')
print(("setting [{}] srid [{}] description [{}] isGeographic[{}]".format(u'Wsg84', da_wsg84.sourceCrs().authid(), da_wsg84.sourceCrs().description(), da_wsg84.sourceCrs().isGeographic())))
# print(("-- projectionAcronym[{}] ellipsoidAcronym[{}] toWkt[{}] mapUnits[{}] toProj4[{}]".format(da_wsg84.sourceCrs().projectionAcronym(),da_wsg84.sourceCrs().ellipsoidAcronym(), da_wsg84.sourceCrs().toWkt(),da_wsg84.sourceCrs().mapUnits(),da_wsg84.sourceCrs().toProj4())))
print(("Testing Position change for[{}] years[{}]".format(u'Ampelanlage - Potsdamer Platz, Verkehrsinsel', u'1924 and 1998')))
# 1924-10-24 SRID=3068;POINT(23099.49 20296.69)
# 1924-10-24 SRID=4326;POINT(13.37650707988041 52.50952361017194)
# 1998-10-02 SRID=3068;POINT(23082.30 20267.80)
# 1998-10-02 SRID=4326;POINT(13.37625537334001 52.50926345498337)
# values returned by spatialite
point_soldner_1924 = QgsPoint(23099.49, 20296.69)
point_soldner_1998 = QgsPoint(23082.30, 20267.80)
distance_soldner_meters = 33.617379
azimuth_soldner_1924 = 3.678339
# ST_Transform(point_soldner_1924,point_soldner_1998,4326)
point_wsg84_1924 = QgsPoint(13.37650707988041, 52.50952361017194)
point_wsg84_1998 = QgsPoint(13.37625537334001, 52.50926345498337)
# ST_Distance(point_wsg84_1924,point_wsg84_1998,1)
distance_wsg84_meters = 33.617302
# ST_Distance(point_wsg84_1924,point_wsg84_1998)
# distance_wsg84_mapunits=0.000362
distance_wsg84_mapunits_format = QgsDistanceArea.formatDistance(0.000362, 7, QgsUnitTypes.DistanceDegrees, True)
# ST_Azimuth(point_wsg84_1924,point_wsg84_1998)
azimuth_wsg84_1924 = 3.674878
# ST_Azimuth(point_wsg84_1998,point_wsg84_1998)
azimuth_wsg84_1998 = 0.533282
# ST_Project(point_wsg84_1924,33.617302,3.674878)
# SRID=4326;POINT(13.37625537318728 52.50926345503591)
point_soldner_1998_project = QgsPoint(13.37625537318728, 52.50926345503591)
# ST_Project(point_wsg84_1998,33.617302,0.533282)
# SRID=4326;POINT(13.37650708009255 52.50952361009799)
point_soldner_1924_project = QgsPoint(13.37650708009255, 52.50952361009799)
distance_qpoint = point_soldner_1924.distance(point_soldner_1998)
azimuth_qpoint = point_soldner_1924.azimuth(point_soldner_1998)
point_soldner_1998_result = point_soldner_1924.project(distance_qpoint, azimuth_qpoint)
point_soldner_1924_result = QgsPoint(0, 0)
point_soldner_1998_result = QgsPoint(0, 0)
# Test meter based projected point from point_1924 to point_1998
length_1998_mapunits, point_soldner_1998_result = da_3068.measureLineProjected(point_soldner_1924, distance_soldner_meters, azimuth_qpoint)
self.assertEqual(point_soldner_1998_result.toString(6), point_soldner_1998.toString(6))
# Test degree based projected point from point_1924 1 meter due East
point_wsg84_meter_result = QgsPoint(0, 0)
point_wsg84_1927_meter = QgsPoint(13.37652180838435, 52.50952361017102)
length_meter_mapunits, point_wsg84_meter_result = da_wsg84.measureLineProjected(point_wsg84_1924, 1.0, (math.pi / 2))
self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, QgsUnitTypes.DistanceDegrees, True), '0.0000147 deg')
self.assertEqual(point_wsg84_meter_result.toString(7), point_wsg84_1927_meter.toString(7))
point_wsg84_1998_result = QgsPoint(0, 0)
length_1928_mapunits, point_wsg84_1998_result = da_wsg84.measureLineProjected(point_wsg84_1924, distance_wsg84_meters, azimuth_wsg84_1924)
self.assertEqual(QgsDistanceArea.formatDistance(length_1928_mapunits, 7, QgsUnitTypes.DistanceDegrees, True), distance_wsg84_mapunits_format)
self.assertEqual(point_wsg84_1998_result.toString(7), point_wsg84_1998.toString(7))
