Python QgsDistanceArea.convertAreaMeasurement方法代码示例

本文整理汇总了Python中qgis.core.QgsDistanceArea.convertAreaMeasurement方法的典型用法代码示例。如果您正苦于以下问题：Python QgsDistanceArea.convertAreaMeasurement方法的具体用法？Python QgsDistanceArea.convertAreaMeasurement怎么用？Python QgsDistanceArea.convertAreaMeasurement使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsDistanceArea的用法示例。

在下文中一共展示了QgsDistanceArea.convertAreaMeasurement方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。

示例1: testAreaMeasureAndUnits

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

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

        polygon = QgsGeometry.fromPolygon(
            [[
                QgsPoint(0, 0), QgsPoint(1, 0), QgsPoint(1, 1), QgsPoint(2, 1), QgsPoint(2, 2), QgsPoint(0, 2), QgsPoint(0, 0),
            ]]
        )

        # We check both the measured area AND the units, in case the logic regarding
        # ellipsoids and units changes in future
        area = da.measureArea(polygon)
        units = da.areaUnits()

        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        assert ((abs(area - 3.0) < 0.00000001 and units == QgsUnitTypes.AreaSquareDegrees) or
                (abs(area - 37176087091.5) < 0.1 and units == QgsUnitTypes.AreaSquareMeters))

        da.setEllipsoid("WGS84")
        area = da.measureArea(polygon)
        units = da.areaUnits()

        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        assert ((abs(area - 3.0) < 0.00000001 and units == QgsUnitTypes.AreaSquareDegrees) or
                (abs(area - 37176087091.5) < 0.1 and units == QgsUnitTypes.AreaSquareMeters))

        da.setEllipsoidalMode(True)
        area = da.measureArea(polygon)
        units = da.areaUnits()

        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        # should always be in Meters Squared
        self.assertAlmostEqual(area, 37416879192.9, delta=0.1)
        self.assertEqual(units, QgsUnitTypes.AreaSquareMeters)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareMiles)
        self.assertAlmostEqual(area, 14446.7378, delta=0.001)

        # now try with a source CRS which is in feet
        polygon = QgsGeometry.fromPolygon(
            [[
                QgsPoint(1850000, 4423000), QgsPoint(1851000, 4423000), QgsPoint(1851000, 4424000), QgsPoint(1852000, 4424000), QgsPoint(1852000, 4425000), QgsPoint(1851000, 4425000), QgsPoint(1850000, 4423000)
            ]]
        )
        da.setSourceCrs(27469)
        da.setEllipsoidalMode(False)
        # measurement should be in square feet
        area = da.measureArea(polygon)
        units = da.areaUnits()
        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(area, 2000000, delta=0.001)
        self.assertEqual(units, QgsUnitTypes.AreaSquareFeet)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareYards)
        self.assertAlmostEqual(area, 222222.2222, delta=0.001)

        da.setEllipsoidalMode(True)
        # now should be in Square Meters again
        area = da.measureArea(polygon)
        units = da.areaUnits()
        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(area, 184149.37, delta=1.0)
        self.assertEqual(units, QgsUnitTypes.AreaSquareMeters)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareYards)
        self.assertAlmostEqual(area, 220240.8172549, delta=1.0)

开发者ID:grizonnetm，项目名称:QGIS，代码行数:80，代码来源:test_qgsdistancearea.py

示例2: testAreaMeasureAndUnits

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

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

        polygon = QgsGeometry.fromPolygonXY(
            [[
                QgsPointXY(0, 0), QgsPointXY(1, 0), QgsPointXY(1, 1), QgsPointXY(2, 1), QgsPointXY(2, 2), QgsPointXY(0, 2), QgsPointXY(0, 0),
            ]]
        )

        # We check both the measured area AND the units, in case the logic regarding
        # ellipsoids and units changes in future
        area = da.measureArea(polygon)
        units = da.areaUnits()

        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        assert ((abs(area - 3.0) < 0.00000001 and units == QgsUnitTypes.AreaSquareDegrees) or
                (abs(area - 37176087091.5) < 0.1 and units == QgsUnitTypes.AreaSquareMeters))

        da.setEllipsoid("WGS84")
        area = da.measureArea(polygon)
        units = da.areaUnits()

        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        # should always be in Meters Squared
        self.assertAlmostEqual(area, 36918093794.121284, delta=0.1)
        self.assertEqual(units, QgsUnitTypes.AreaSquareMeters)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareMiles)
        self.assertAlmostEqual(area, 14254.155703182701, delta=0.001)

        # now try with a source CRS which is in feet
        polygon = QgsGeometry.fromPolygonXY(
            [[
                QgsPointXY(1850000, 4423000), QgsPointXY(1851000, 4423000), QgsPointXY(1851000, 4424000), QgsPointXY(1852000, 4424000), QgsPointXY(1852000, 4425000), QgsPointXY(1851000, 4425000), QgsPointXY(1850000, 4423000)
            ]]
        )
        da.setSourceCrs(QgsCoordinateReferenceSystem.fromSrsId(27469), QgsProject.instance().transformContext())
        da.setEllipsoid("NONE")
        # measurement should be in square feet
        area = da.measureArea(polygon)
        units = da.areaUnits()
        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(area, 2000000, delta=0.001)
        self.assertEqual(units, QgsUnitTypes.AreaSquareFeet)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareYards)
        self.assertAlmostEqual(area, 222222.2222, delta=0.001)

        da.setEllipsoid("WGS84")
        # now should be in Square Meters again
        area = da.measureArea(polygon)
        units = da.areaUnits()
        print(("measured {} in {}".format(area, QgsUnitTypes.toString(units))))
        self.assertAlmostEqual(area, 185818.59096575077, delta=1.0)
        self.assertEqual(units, QgsUnitTypes.AreaSquareMeters)

        # test converting the resultant area
        area = da.convertAreaMeasurement(area, QgsUnitTypes.AreaSquareYards)
        self.assertAlmostEqual(area, 222237.18521272976, delta=1.0)

开发者ID:phborba，项目名称:QGIS，代码行数:69，代码来源:test_qgsdistancearea.py

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