Python QgsDistanceArea.lengthUnits方法代码示例

# 需要导入模块: from qgis.core import QgsDistanceArea [as 别名]
# 或者: from qgis.core.QgsDistanceArea import lengthUnits [as 别名]
    def testLengthMeasureAndUnits(self):
        """Test a variety of length measurements in different CRS and ellipsoid modes, to check that the
           calculated lengths and units are always consistent
        """

        da = QgsDistanceArea()
        da.setSourceCrs(QgsCoordinateReferenceSystem.fromSrsId(3452), QgsProject.instance().transformContext())
        da.setEllipsoid("NONE")

        # We check both the measured length AND the units, in case the logic regarding
        # ellipsoids and units changes in future
        distance = da.measureLine(QgsPointXY(1, 1), QgsPointXY(2, 3))
        units = da.lengthUnits()

        print(("measured {} in {}".format(distance, QgsUnitTypes.toString(units))))
        assert ((abs(distance - 2.23606797) < 0.00000001 and units == QgsUnitTypes.DistanceDegrees) or
                (abs(distance - 248.52) < 0.01 and units == QgsUnitTypes.DistanceMeters))

        da.setEllipsoid("WGS84")
        distance = da.measureLine(QgsPointXY(1, 1), QgsPointXY(2, 3))
        units = da.lengthUnits()

        print(("measured {} in {}".format(distance, QgsUnitTypes.toString(units))))
        # should always be in Meters
        self.assertAlmostEqual(distance, 247555.57, delta=0.01)
        self.assertEqual(units, QgsUnitTypes.DistanceMeters)

        # test converting the resultant length
        distance = da.convertLengthMeasurement(distance, QgsUnitTypes.DistanceNauticalMiles)
        self.assertAlmostEqual(distance, 133.669, delta=0.01)

        # now try with a source CRS which is in feet
        da.setSourceCrs(QgsCoordinateReferenceSystem.fromSrsId(27469), QgsProject.instance().transformContext())
        da.setEllipsoid("NONE")
        # measurement should be in feet
        distance = da.measureLine(QgsPointXY(1, 1), QgsPointXY(2, 3))
        units = da.lengthUnits()
        print(("measured {} in {}".format(distance, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(distance, 2.23606797, delta=0.000001)
        self.assertEqual(units, QgsUnitTypes.DistanceFeet)

        # test converting the resultant length
        distance = da.convertLengthMeasurement(distance, QgsUnitTypes.DistanceMeters)
        self.assertAlmostEqual(distance, 0.6815, delta=0.001)

        da.setEllipsoid("WGS84")
        # now should be in Meters again
        distance = da.measureLine(QgsPointXY(1, 1), QgsPointXY(2, 3))
        units = da.lengthUnits()
        print(("measured {} in {}".format(distance, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(distance, 0.67953772, delta=0.000001)
        self.assertEqual(units, QgsUnitTypes.DistanceMeters)

        # test converting the resultant length
        distance = da.convertLengthMeasurement(distance, QgsUnitTypes.DistanceFeet)
        self.assertAlmostEqual(distance, 2.2294, delta=0.001)

# 需要导入模块: from qgis.core import QgsDistanceArea [as 别名]
# 或者: from qgis.core.QgsDistanceArea import lengthUnits [as 别名]
    def testLengthMeasureAndUnits(self):
        """Test a variety of length measurements in different CRS and ellipsoid modes, to check that the
           calculated lengths and units are always consistent
        """

        da = QgsDistanceArea()
        da.setSourceCrs(3452)
        da.setEllipsoidalMode(False)
        da.setEllipsoid("NONE")
        daCRS = QgsCoordinateReferenceSystem()
        daCRS.createFromSrsId(da.sourceCrs())

        # We check both the measured length AND the units, in case the logic regarding
        # ellipsoids and units changes in future
        distance = da.measureLine(QgsPoint(1, 1), QgsPoint(2, 3))
        units = da.lengthUnits()

        print "measured {} in {}".format(distance, QgsUnitTypes.toString(units))
        assert ((abs(distance - 2.23606797) < 0.00000001 and units == QGis.Degrees) or
                (abs(distance - 248.52) < 0.01 and units == QGis.Meters))

        da.setEllipsoid("WGS84")
        distance = da.measureLine(QgsPoint(1, 1), QgsPoint(2, 3))
        units = da.lengthUnits()

        print "measured {} in {}".format(distance, QgsUnitTypes.toString(units))
        assert ((abs(distance - 2.23606797) < 0.00000001 and units == QGis.Degrees) or
                (abs(distance - 248.52) < 0.01 and units == QGis.Meters))

        da.setEllipsoidalMode(True)
        distance = da.measureLine(QgsPoint(1, 1), QgsPoint(2, 3))
        units = da.lengthUnits()

        print "measured {} in {}".format(distance, QgsUnitTypes.toString(units))
        # should always be in Meters
        self.assertAlmostEqual(distance, 247555.57, delta=0.01)
        self.assertEqual(units, QGis.Meters)

        # now try with a source CRS which is in feet
        da.setSourceCrs(27469)
        da.setEllipsoidalMode(False)
        # measurement should be in feet
        distance = da.measureLine(QgsPoint(1, 1), QgsPoint(2, 3))
        units = da.lengthUnits()
        print "measured {} in {}".format(distance, QgsUnitTypes.toString(units))
        self.assertAlmostEqual(distance, 2.23606797, delta=0.000001)
        self.assertEqual(units, QGis.Feet)

        da.setEllipsoidalMode(True)
        # now should be in Meters again
        distance = da.measureLine(QgsPoint(1, 1), QgsPoint(2, 3))
        units = da.lengthUnits()
        print "measured {} in {}".format(distance, QgsUnitTypes.toString(units))
        self.assertAlmostEqual(distance, 0.67953772, delta=0.000001)
        self.assertEqual(units, QGis.Meters)

# 需要导入模块: from qgis.core import QgsDistanceArea [as 别名]
# 或者: from qgis.core.QgsDistanceArea import lengthUnits [as 别名]
    def testMeasureLineProjectedWorldPoints(self):
        #   +-+
        #   | |
        # +-+ +
        # checking returned length_mapunits/projected_points of diffferent world points with results from SpatiaLite ST_Project
        da_3068 = QgsDistanceArea()
        da_3068.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:3068'), QgsProject.instance().transformContext())
        if (da_3068.sourceCrs().isGeographic()):
            da_3068.setEllipsoid(da_3068.sourceCrs().ellipsoidAcronym())
        self.assertEqual(da_3068.sourceCrs().authid(), 'EPSG:3068')
        print(("setting [{}] srid [{}] description [{}] isGeographic[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}]".format(u'EPSG:3068', da_3068.sourceCrs().authid(), da_3068.sourceCrs().description(), da_3068.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_3068.lengthUnits()), da_3068.sourceCrs().projectionAcronym(), da_3068.sourceCrs().ellipsoidAcronym())))
        da_wsg84 = QgsDistanceArea()
        da_wsg84.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:4326'), QgsProject.instance().transformContext())
        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[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}] ellipsoid[{}]".format(u'EPSG:4326', da_wsg84.sourceCrs().authid(), da_wsg84.sourceCrs().description(), da_wsg84.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_wsg84.lengthUnits()), da_wsg84.sourceCrs().projectionAcronym(), da_wsg84.sourceCrs().ellipsoidAcronym(), da_wsg84.ellipsoid())))
        da_4314 = QgsDistanceArea()
        da_4314.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:4314'), QgsProject.instance().transformContext())
        if (da_4314.sourceCrs().isGeographic()):
            da_4314.setEllipsoid(da_4314.sourceCrs().ellipsoidAcronym())
        self.assertEqual(da_4314.sourceCrs().authid(), 'EPSG:4314')
        print(("setting [{}] srid [{}] description [{}] isGeographic[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}]".format(u'EPSG:4314', da_4314.sourceCrs().authid(), da_4314.sourceCrs().description(), da_4314.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_4314.lengthUnits()), da_4314.sourceCrs().projectionAcronym(), da_4314.sourceCrs().ellipsoidAcronym())))
        da_4805 = QgsDistanceArea()
        da_4805.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:4805'), QgsProject.instance().transformContext())
        if (da_4805.sourceCrs().isGeographic()):
            da_4805.setEllipsoid(da_4805.sourceCrs().ellipsoidAcronym())
        self.assertEqual(da_4805.sourceCrs().authid(), 'EPSG:4805')
        print(("setting [{}] srid [{}] description [{}] isGeographic[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}]".format(u'EPSG:4805', da_4805.sourceCrs().authid(), da_4805.sourceCrs().description(), da_4805.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_4805.lengthUnits()), da_4805.sourceCrs().projectionAcronym(), da_4805.sourceCrs().ellipsoidAcronym())))
        # EPSG:5665 unknown, why?
        da_5665 = QgsDistanceArea()
        da_5665.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:5665'), QgsProject.instance().transformContext())
        if (da_5665.sourceCrs().isGeographic()):
            da_5665.setEllipsoid(da_5665.sourceCrs().ellipsoidAcronym())
        print(("setting [{}] srid [{}] description [{}] isGeographic[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}]".format(u'EPSG:5665', da_5665.sourceCrs().authid(), da_5665.sourceCrs().description(), da_5665.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_5665.lengthUnits()), da_5665.sourceCrs().projectionAcronym(), da_5665.sourceCrs().ellipsoidAcronym())))
        #self.assertEqual(da_5665.sourceCrs().authid(), 'EPSG:5665')
        da_25833 = QgsDistanceArea()
        da_25833.setSourceCrs(QgsCoordinateReferenceSystem.fromOgcWmsCrs('EPSG:25833'), QgsProject.instance().transformContext())
        if (da_25833.sourceCrs().isGeographic()):
            da_25833.setEllipsoid(da_25833.sourceCrs().ellipsoidAcronym())
        print(("setting [{}] srid [{}] description [{}] isGeographic[{}] lengthUnits[{}] projectionAcronym[{}] ellipsoidAcronym[{}]".format(u'EPSG:25833', da_25833.sourceCrs().authid(), da_25833.sourceCrs().description(), da_25833.sourceCrs().isGeographic(), QgsUnitTypes.toString(da_25833.lengthUnits()), da_25833.sourceCrs().projectionAcronym(), da_25833.sourceCrs().ellipsoidAcronym())))
        self.assertEqual(da_25833.sourceCrs().authid(), 'EPSG:25833')

        # Berlin - Brandenburg Gate - Quadriga
        point_berlin_3068 = QgsPointXY(23183.38449999984, 21047.3225000017)
        point_berlin_3068_project = point_berlin_3068.project(1, (math.pi / 2))
        point_meter_result = QgsPointXY(0, 0)
        length_meter_mapunits, point_meter_result = da_3068.measureLineProjected(point_berlin_3068, 1.0, (math.pi / 2))
        pprint(point_meter_result)
        print('-I-> Berlin 3068 length_meter_mapunits[{}] point_meter_result[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_3068.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 1, da_3068.lengthUnits(), True), '1.0 m')
        self.assertEqual(point_meter_result.toString(7), point_berlin_3068_project.toString(7))
        point_berlin_wsg84 = QgsPointXY(13.37770458660236, 52.51627178856762)
        point_berlin_wsg84_project = QgsPointXY(13.37771931736259, 52.51627178856669)
        length_meter_mapunits, point_meter_result = da_wsg84.measureLineProjected(point_berlin_wsg84, 1.0, (math.pi / 2))
        print('-I-> Berlin Wsg84 length_meter_mapunits[{}] point_meter_result[{}] ellipsoid[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 20, da_wsg84.lengthUnits(), True), point_meter_result.asWkt(), da_wsg84.ellipsoid()))
        # for unknown reasons, this is returning '0.00001473026 m' instead of '0.00001473026 deg' when using da_wsg84.lengthUnits()
        # self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits,11,da_wsg84.lengthUnits(),True), '0.00001473026 deg')
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 11, QgsUnitTypes.DistanceDegrees, True), '0.00001473026 deg')
        self.assertEqual(point_meter_result.toString(7), point_berlin_wsg84_project.toString(7))
        point_berlin_4314 = QgsPointXY(13.37944343021465, 52.51767872437083)
        point_berlin_4314_project = QgsPointXY(13.37945816324759, 52.5176787243699)
        length_meter_mapunits, point_meter_result = da_4314.measureLineProjected(point_berlin_4314, 1.0, (math.pi / 2))
        print('-I-> Berlin 4314 length_meter_mapunits[{}] point_meter_result[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_4314.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 9, QgsUnitTypes.DistanceDegrees, True), '0.000014733 deg')
        self.assertEqual(point_meter_result.toString(7), point_berlin_4314_project.toString(7))
        point_berlin_4805 = QgsPointXY(31.04960570069176, 52.5174657497405)
        point_berlin_4805_project = QgsPointXY(31.04962043365347, 52.51746574973957)
        length_meter_mapunits, point_meter_result = da_4805.measureLineProjected(point_berlin_4805, 1.0, (math.pi / 2))
        print('-I-> Berlin 4805 length_meter_mapunits[{}] point_meter_result[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_4805.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 9, QgsUnitTypes.DistanceDegrees, True), '0.000014733 deg')
        self.assertEqual(point_meter_result.toString(7), point_berlin_4805_project.toString(7))
        point_berlin_25833 = QgsPointXY(389918.0748318382, 5819698.772194743)
        point_berlin_25833_project = point_berlin_25833.project(1, (math.pi / 2))
        length_meter_mapunits, point_meter_result = da_25833.measureLineProjected(point_berlin_25833, 1.0, (math.pi / 2))
        print('-I-> Berlin 25833 length_meter_mapunits[{}] point_meter_result[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_25833.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_25833.lengthUnits(), True), '1.0000000 m')
        self.assertEqual(point_meter_result.toString(7), point_berlin_25833_project.toString(7))
        if da_5665.sourceCrs().authid() != "":
            point_berlin_5665 = QgsPointXY(3389996.871728864, 5822169.719727578)
            point_berlin_5665_project = point_berlin_5665.project(1, (math.pi / 2))
            length_meter_mapunits, point_meter_result = da_5665.measureLineProjected(point_berlin_5665, 1.0, (math.pi / 2))
            print('-I-> Berlin 5665 length_meter_mapunits[{}] point_meter_result[{}]'.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_5665.lengthUnits(), True), point_meter_result.asWkt()))
            self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 1.0, da_5665.lengthUnits(), True), '1.0 m')
            self.assertEqual(point_meter_result.toString(7), point_berlin_5665_project.toString(7))
        print('\n12 points ''above over'' and on the Equator')
        point_wsg84 = QgsPointXY(25.7844, 71.1725)
        point_wsg84_project = QgsPointXY(25.78442775215388, 71.17249999999795)
        length_meter_mapunits, point_meter_result = da_wsg84.measureLineProjected(point_wsg84, 1.0, (math.pi / 2))
        print('-I-> Nordkap, Norway - Wsg84 - length_meter_mapunits[{}] point_meter_result[{}] '.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_wsg84.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, QgsUnitTypes.DistanceDegrees, True), '0.0000278 deg')
        self.assertEqual(point_meter_result.toString(7), point_wsg84_project.toString(7))
        point_wsg84 = QgsPointXY(24.95995, 60.16841)
        point_wsg84_project = QgsPointXY(24.95996801277454, 60.16840999999877)
        length_meter_mapunits, point_meter_result = da_wsg84.measureLineProjected(point_wsg84, 1.0, (math.pi / 2))
        print('-I-> Helsinki, Finnland - Wsg84 - length_meter_mapunits[{}] point_meter_result[{}] '.format(QgsDistanceArea.formatDistance(length_meter_mapunits, 7, da_wsg84.lengthUnits(), True), point_meter_result.asWkt()))
        self.assertEqual(QgsDistanceArea.formatDistance(length_meter_mapunits, 8, QgsUnitTypes.DistanceDegrees, True), '0.00001801 deg')
        self.assertEqual(point_meter_result.toString(7), point_wsg84_project.toString(7))
        point_wsg84 = QgsPointXY(12.599278, 55.692861)
        point_wsg84_project = QgsPointXY(12.59929390161872, 55.69286099999897)
#.........这里部分代码省略.........

# 需要导入模块: from qgis.core import QgsDistanceArea [as 别名]
# 或者: from qgis.core.QgsDistanceArea import lengthUnits [as 别名]
class SizeCalculator():

    """Special object to handle size calculation with an output unit."""

    def __init__(
            self, coordinate_reference_system, geometry_type, exposure_key):
        """Constructor for the size calculator.

        :param coordinate_reference_system: The Coordinate Reference System of
            the layer.
        :type coordinate_reference_system: QgsCoordinateReferenceSystem

        :param exposure_key: The geometry type of the layer.
        :type exposure_key: qgis.core.QgsWkbTypes.GeometryType
        """
        self.calculator = QgsDistanceArea()
        self.calculator.setSourceCrs(
            coordinate_reference_system,
            QgsProject.instance().transformContext()
        )
        self.calculator.setEllipsoid('WGS84')

        if geometry_type == QgsWkbTypes.LineGeometry:
            self.default_unit = unit_metres
            LOGGER.info('The size calculator is set to use {unit}'.format(
                unit=distance_unit[self.calculator.lengthUnits()]))
        else:
            self.default_unit = unit_square_metres
            LOGGER.info('The size calculator is set to use {unit}'.format(
                unit=distance_unit[self.calculator.areaUnits()]))
        self.geometry_type = geometry_type
        self.output_unit = None
        if exposure_key:
            exposure_definition = definition(exposure_key)
            self.output_unit = exposure_definition['size_unit']

    def measure_distance(self, point_a, point_b):
        """Measure the distance between two points.

        This is added here since QgsDistanceArea object is already called here.

        :param point_a: First Point.
        :type point_a: QgsPoint

        :param point_b: Second Point.
        :type point_b: QgsPoint

        :return: The distance between input points.
        :rtype: float
        """
        return self.calculator.measureLine(point_a, point_b)

    def measure(self, geometry):
        """Measure the length or the area of a geometry.

        :param geometry: The geometry.
        :type geometry: QgsGeometry

        :return: The geometric size in the expected exposure unit.
        :rtype: float
        """
        message = 'Size with NaN value : geometry valid={valid}, WKT={wkt}'
        feature_size = 0
        if geometry.isMultipart():
            # Be careful, the size calculator is not working well on a
            # multipart.
            # So we compute the size part per part. See ticket #3812
            for single in geometry.asGeometryCollection():
                if self.geometry_type == QgsWkbTypes.LineGeometry:
                    geometry_size = self.calculator.measureLength(single)
                else:
                    geometry_size = self.calculator.measureArea(single)
                if not isnan(geometry_size):
                    feature_size += geometry_size
                else:
                    LOGGER.debug(message.format(
                        valid=single.isGeosValid(),
                        wkt=single.asWkt()))
        else:
            if self.geometry_type == QgsWkbTypes.LineGeometry:
                geometry_size = self.calculator.measureLength(geometry)
            else:
                geometry_size = self.calculator.measureArea(geometry)
            if not isnan(geometry_size):
                feature_size = geometry_size
            else:
                LOGGER.debug(message.format(
                    valid=geometry.isGeosValid(),
                    wkt=geometry.asWkt()))

        feature_size = round(feature_size)

        if self.output_unit:
            if self.output_unit != self.default_unit:
                feature_size = convert_unit(
                    feature_size, self.default_unit, self.output_unit)

        return feature_size