本文整理汇总了Python中qgis.core.QgsCoordinateReferenceSystem.toProj4方法的典型用法代码示例。如果您正苦于以下问题：Python QgsCoordinateReferenceSystem.toProj4方法的具体用法？Python QgsCoordinateReferenceSystem.toProj4怎么用？Python QgsCoordinateReferenceSystem.toProj4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.QgsCoordinateReferenceSystem的用法示例。
在下文中一共展示了QgsCoordinateReferenceSystem.toProj4方法的5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: __signal_pbCopyKml_clicked
# 需要导入模块: from qgis.core import QgsCoordinateReferenceSystem [as 别名]
# 或者: from qgis.core.QgsCoordinateReferenceSystem import toProj4 [as 别名]
def __signal_pbCopyKml_clicked(self, cheked):
# Extent Openlayers
action = "map.getExtent().toGeometry().toString();"
wkt = self.webViewMap.page().mainFrame().evaluateJavaScript(action)
rect = QgsGeometry.fromWkt(wkt).boundingBox()
srsGE = QgsCoordinateReferenceSystem(
4326, QgsCoordinateReferenceSystem.EpsgCrsId)
coodTrans = QgsCoordinateTransform(self.__srsOL, srsGE,
QgsProject.instance())
rect = coodTrans.transform(
rect, QgsCoordinateTransform.ForwardTransform)
line = QgsGeometry.fromRect(rect).asPolygon()[0]
wkt = str(QgsGeometry.fromPolylineXY(line).asWkt())
# Kml
proj4 = str(srsGE.toProj4())
kmlLine = bindogr.exportKml(wkt, proj4)
kml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"\
"<kml xmlns=\"http://www.opengis.net/kml/2.2\" " \
"xmlns:gx=\"http://www.google.com/kml/ext/2.2\" " \
"xmlns:kml=\"http://www.opengis.net/kml/2.2\" " \
"xmlns:atom=\"http://www.w3.org/2005/Atom\">" \
"<Placemark>" \
"<name>KML from Plugin Openlayers Overview for QGIS</name>" \
"<description>Extent of openlayers map from Plugin Openlayers \
Overview for QGIS</description>"\
"%s" \
"</Placemark></kml>" % kmlLine
clipBoard = QApplication.clipboard()
clipBoard.setText(kml)示例2: test_ExpressionFieldEllipsoidLengthCalculation
# 需要导入模块: from qgis.core import QgsCoordinateReferenceSystem [as 别名]
# 或者: from qgis.core.QgsCoordinateReferenceSystem import toProj4 [as 别名]
def test_ExpressionFieldEllipsoidLengthCalculation(self):
#create a temporary layer
temp_layer = QgsVectorLayer("LineString?crs=epsg:3111&field=pk:int", "vl", "memory")
self.assertTrue(temp_layer.isValid())
f1 = QgsFeature(temp_layer.dataProvider().fields(), 1)
f1.setAttribute("pk", 1)
f1.setGeometry(QgsGeometry.fromPolyline([QgsPoint(2484588, 2425722), QgsPoint(2482767, 2398853)]))
temp_layer.dataProvider().addFeatures([f1])
# set project CRS and ellipsoid
srs = QgsCoordinateReferenceSystem(3111, QgsCoordinateReferenceSystem.EpsgCrsId)
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCRSProj4String", srs.toProj4())
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCRSID", srs.srsid())
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCrs", srs.authid())
QgsProject.instance().writeEntry("Measure", "/Ellipsoid", "WGS84")
QgsProject.instance().writeEntry("Measurement", "/DistanceUnits", QgsUnitTypes.encodeUnit(QGis.Meters))
idx = temp_layer.addExpressionField('$length', QgsField('length', QVariant.Double)) # NOQA
# check value
f = temp_layer.getFeatures().next()
expected = 26932.156
self.assertAlmostEqual(f['length'], expected, 3)
# change project length unit, check calculation respects unit
QgsProject.instance().writeEntry("Measurement", "/DistanceUnits", QgsUnitTypes.encodeUnit(QGis.Feet))
f = temp_layer.getFeatures().next()
expected = 88360.0918635
self.assertAlmostEqual(f['length'], expected, 3)示例3: test_ExpressionFieldEllipsoidAreaCalculation
# 需要导入模块: from qgis.core import QgsCoordinateReferenceSystem [as 别名]
# 或者: from qgis.core.QgsCoordinateReferenceSystem import toProj4 [as 别名]
def test_ExpressionFieldEllipsoidAreaCalculation(self):
#create a temporary layer
temp_layer = QgsVectorLayer("Polygon?crs=epsg:3111&field=pk:int", "vl", "memory")
self.assertTrue(temp_layer.isValid())
f1 = QgsFeature(temp_layer.dataProvider().fields(), 1)
f1.setAttribute("pk", 1)
f1.setGeometry(QgsGeometry.fromPolygon([[QgsPoint(2484588, 2425722), QgsPoint(2482767, 2398853), QgsPoint(2520109, 2397715), QgsPoint(2520792, 2425494), QgsPoint(2484588, 2425722)]]))
temp_layer.dataProvider().addFeatures([f1])
# set project CRS and ellipsoid
srs = QgsCoordinateReferenceSystem(3111, QgsCoordinateReferenceSystem.EpsgCrsId)
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCRSProj4String", srs.toProj4())
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCRSID", srs.srsid())
QgsProject.instance().writeEntry("SpatialRefSys", "/ProjectCrs", srs.authid())
QgsProject.instance().writeEntry("Measure", "/Ellipsoid", "WGS84")
QgsProject.instance().writeEntry("Measurement", "/AreaUnits", QgsUnitTypes.encodeUnit(QgsUnitTypes.SquareMeters))
idx = temp_layer.addExpressionField('$area', QgsField('area', QVariant.Double)) # NOQA
# check value
f = temp_layer.getFeatures().next()
expected = 1009089817.0
self.assertAlmostEqual(f['area'], expected, delta=1.0)
# change project area unit, check calculation respects unit
QgsProject.instance().writeEntry("Measurement", "/AreaUnits", QgsUnitTypes.encodeUnit(QgsUnitTypes.SquareMiles))
f = temp_layer.getFeatures().next()
expected = 389.6117565069
self.assertAlmostEqual(f['area'], expected, 3)示例4: browseCRS
# 需要导入模块: from qgis.core import QgsCoordinateReferenceSystem [as 别名]
# 或者: from qgis.core.QgsCoordinateReferenceSystem import toProj4 [as 别名]
def browseCRS(self):
selector = QgsGenericProjectionSelector()
selector.setSelectedAuthId(self.crs)
if selector.exec_():
authId = selector.selectedAuthId()
if authId.upper().startswith("EPSG:"):
self.crs = authId
else:
proj = QgsCoordinateReferenceSystem()
proj.createFromSrsId(selector.selectedCrsId())
self.crs = proj.toProj4()
self.updateText()示例5: gdal_crs_string
# 需要导入模块: from qgis.core import QgsCoordinateReferenceSystem [as 别名]
# 或者: from qgis.core.QgsCoordinateReferenceSystem import toProj4 [as 别名]
def gdal_crs_string(crs: QgsCoordinateReferenceSystem) -> str:
"""
Converts a QgsCoordinateReferenceSystem to a string understandable
by GDAL
:param crs: crs to convert
:return: gdal friendly string
"""
if crs.authid().upper().startswith('EPSG:'):
return crs.authid()
# fallback to proj4 string
return crs.toProj4()