本文整理汇总了Python中qgis.core.QgsRectangle.area方法的典型用法代码示例。如果您正苦于以下问题：Python QgsRectangle.area方法的具体用法？Python QgsRectangle.area怎么用？Python QgsRectangle.area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.QgsRectangle的用法示例。
在下文中一共展示了QgsRectangle.area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: processAlgorithm
# 需要导入模块: from qgis.core import QgsRectangle [as 别名]
# 或者: from qgis.core.QgsRectangle import area [as 别名]
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
field_name = self.parameterAsString(parameters, self.FIELD, context)
type = self.parameterAsEnum(parameters, self.TYPE, context)
use_field = bool(field_name)
field_index = -1
fields = QgsFields()
fields.append(QgsField('id', QVariant.Int, '', 20))
if use_field:
# keep original field type, name and parameters
field_index = source.fields().lookupField(field_name)
if field_index >= 0:
fields.append(source.fields()[field_index])
if type == 0:
# envelope
fields.append(QgsField('width', QVariant.Double, '', 20, 6))
fields.append(QgsField('height', QVariant.Double, '', 20, 6))
fields.append(QgsField('area', QVariant.Double, '', 20, 6))
fields.append(QgsField('perimeter', QVariant.Double, '', 20, 6))
elif type == 1:
# oriented rect
fields.append(QgsField('width', QVariant.Double, '', 20, 6))
fields.append(QgsField('height', QVariant.Double, '', 20, 6))
fields.append(QgsField('angle', QVariant.Double, '', 20, 6))
fields.append(QgsField('area', QVariant.Double, '', 20, 6))
fields.append(QgsField('perimeter', QVariant.Double, '', 20, 6))
elif type == 2:
# circle
fields.append(QgsField('radius', QVariant.Double, '', 20, 6))
fields.append(QgsField('area', QVariant.Double, '', 20, 6))
elif type == 3:
# convex hull
fields.append(QgsField('area', QVariant.Double, '', 20, 6))
fields.append(QgsField('perimeter', QVariant.Double, '', 20, 6))
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.Polygon, source.sourceCrs())
if sink is None:
raise QgsProcessingException(self.invalidSinkError(parameters, self.OUTPUT))
if field_index >= 0:
geometry_dict = {}
bounds_dict = {}
total = 50.0 / source.featureCount() if source.featureCount() else 1
features = source.getFeatures(QgsFeatureRequest().setSubsetOfAttributes([field_index]))
for current, f in enumerate(features):
if feedback.isCanceled():
break
if not f.hasGeometry():
continue
if type == 0:
# bounding boxes - calculate on the fly for efficiency
if not f.attributes()[field_index] in bounds_dict:
bounds_dict[f.attributes()[field_index]] = f.geometry().boundingBox()
else:
bounds_dict[f.attributes()[field_index]].combineExtentWith(f.geometry().boundingBox())
else:
if not f.attributes()[field_index] in geometry_dict:
geometry_dict[f.attributes()[field_index]] = [f.geometry()]
else:
geometry_dict[f.attributes()[field_index]].append(f.geometry())
feedback.setProgress(int(current * total))
if type == 0:
# bounding boxes
current = 0
total = 50.0 / len(bounds_dict) if bounds_dict else 1
for group, rect in bounds_dict.items():
if feedback.isCanceled():
break
# envelope
feature = QgsFeature()
feature.setGeometry(QgsGeometry.fromRect(rect))
feature.setAttributes([current, group, rect.width(), rect.height(), rect.area(), rect.perimeter()])
sink.addFeature(feature, QgsFeatureSink.FastInsert)
geometry_dict[group] = None
feedback.setProgress(50 + int(current * total))
current += 1
else:
current = 0
total = 50.0 / len(geometry_dict) if geometry_dict else 1
for group, geometries in geometry_dict.items():
if feedback.isCanceled():
break
feature = self.createFeature(feedback, current, type, geometries, group)
sink.addFeature(feature, QgsFeatureSink.FastInsert)
geometry_dict[group] = None
#.........这里部分代码省略.........
示例2: testCalculations
# 需要导入模块: from qgis.core import QgsRectangle [as 别名]
# 或者: from qgis.core.QgsRectangle import area [as 别名]
def testCalculations(self):
rect = QgsRectangle(0.0, 1.0, 20.0, 10.0)
self.assertEqual(rect.area(), 180.0)
self.assertEqual(rect.perimeter(), 58.0)