本文整理汇总了Python中qgis.analysis.QgsGraphBuilder类的典型用法代码示例。如果您正苦于以下问题：Python QgsGraphBuilder类的具体用法？Python QgsGraphBuilder怎么用？Python QgsGraphBuilder使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了QgsGraphBuilder类的7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
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
if network is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
startPoint = self.parameterAsPoint(parameters, self.START_POINT, context, network.sourceCrs())
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
travelCost = self.parameterAsDouble(parameters, self.TRAVEL_COST, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
include_bounds = True # default to true to maintain 3.0 API
if self.INCLUDE_BOUNDS in parameters:
include_bounds = self.parameterAsBool(parameters, self.INCLUDE_BOUNDS, context)
directionField = -1
if directionFieldName:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
director.addStrategy(strategy)
builder = QgsGraphBuilder(network.sourceCrs(),
True,
tolerance)
feedback.pushInfo(QCoreApplication.translate('ServiceAreaFromPoint', 'Building graph…'))
snappedPoints = director.makeGraph(builder, [startPoint], feedback)
feedback.pushInfo(QCoreApplication.translate('ServiceAreaFromPoint', 'Calculating service area…'))
graph = builder.graph()
idxStart = graph.findVertex(snappedPoints[0])
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
vertices = set()
points = []
lines = []
for vertex, start_vertex_cost in enumerate(cost):
inbound_edge_index = tree[vertex]
if inbound_edge_index == -1 and vertex != idxStart:
# unreachable vertex
continue
if start_vertex_cost > travelCost:
# vertex is too expensive, discard
continue
vertices.add(vertex)
start_point = graph.vertex(vertex).point()
# find all edges coming from this vertex
for edge_id in graph.vertex(vertex).outgoingEdges():
edge = graph.edge(edge_id)
end_vertex_cost = start_vertex_cost + edge.cost(0)
end_point = graph.vertex(edge.toVertex()).point()
if end_vertex_cost <= travelCost:
# end vertex is cheap enough to include
vertices.add(edge.toVertex())
lines.append([start_point, end_point])
else:
# travelCost sits somewhere on this edge, interpolate position
interpolated_end_point = QgsGeometryUtils.interpolatePointOnLineByValue(start_point.x(), start_point.y(), start_vertex_cost,
end_point.x(), end_point.y(), end_vertex_cost, travelCost)
points.append(interpolated_end_point)
lines.append([start_point, interpolated_end_point])
for i in vertices:
points.append(graph.vertex(i).point())
feedback.pushInfo(QCoreApplication.translate('ServiceAreaFromPoint', 'Writing results…'))
fields = QgsFields()
fields.append(QgsField('type', QVariant.String, '', 254, 0))
fields.append(QgsField('start', QVariant.String, '', 254, 0))
feat = QgsFeature()
#.........这里部分代码省略.........
示例2: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
if network is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
startPoints = self.parameterAsSource(parameters, self.START_POINTS, context)
if startPoints is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.START_POINTS))
endPoint = self.parameterAsPoint(parameters, self.END_POINT, context, network.sourceCrs())
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
fields = startPoints.fields()
fields.append(QgsField('start', QVariant.String, '', 254, 0))
fields.append(QgsField('end', QVariant.String, '', 254, 0))
fields.append(QgsField('cost', QVariant.Double, '', 20, 7))
feat = QgsFeature()
feat.setFields(fields)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.LineString, network.sourceCrs())
if sink is None:
raise QgsProcessingException(self.invalidSinkError(parameters, self.OUTPUT))
directionField = -1
if directionFieldName:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
multiplier = 3600
director.addStrategy(strategy)
builder = QgsGraphBuilder(network.sourceCrs(),
True,
tolerance)
feedback.pushInfo(QCoreApplication.translate('ShortestPathLayerToPoint', 'Loading start points…'))
request = QgsFeatureRequest()
request.setDestinationCrs(network.sourceCrs(), context.transformContext())
features = startPoints.getFeatures(request)
total = 100.0 / startPoints.featureCount() if startPoints.featureCount() else 0
points = [endPoint]
source_attributes = {}
i = 1
for current, f in enumerate(features):
if feedback.isCanceled():
break
if not f.hasGeometry():
continue
for p in f.geometry().vertices():
points.append(QgsPointXY(p))
source_attributes[i] = f.attributes()
i += 1
feedback.setProgress(int(current * total))
feedback.pushInfo(QCoreApplication.translate('ShortestPathLayerToPoint', 'Building graph…'))
snappedPoints = director.makeGraph(builder, points, feedback)
feedback.pushInfo(QCoreApplication.translate('ShortestPathLayerToPoint', 'Calculating shortest paths…'))
graph = builder.graph()
idxEnd = graph.findVertex(snappedPoints[0])
nPoints = len(snappedPoints)
total = 100.0 / nPoints if nPoints else 1
for i in range(1, nPoints):
if feedback.isCanceled():
break
#.........这里部分代码省略.........
示例3: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
startPoints = self.parameterAsSource(parameters, self.START_POINTS, context)
endPoint = self.parameterAsPoint(parameters, self.END_POINT, context)
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
fields = QgsFields()
fields.append(QgsField('start', QVariant.String, '', 254, 0))
fields.append(QgsField('end', QVariant.String, '', 254, 0))
fields.append(QgsField('cost', QVariant.Double, '', 20, 7))
feat = QgsFeature()
feat.setFields(fields)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.LineString, network.sourceCrs())
directionField = -1
if directionFieldName:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
multiplier = 3600
director.addStrategy(strategy)
builder = QgsGraphBuilder(context.project().crs(),
True,
tolerance)
feedback.pushInfo(self.tr('Loading start points...'))
request = QgsFeatureRequest()
request.setFlags(request.flags() ^ QgsFeatureRequest.SubsetOfAttributes)
request.setDestinationCrs(network.sourceCrs())
features = startPoints.getFeatures(request)
total = 100.0 / startPoints.featureCount() if startPoints.featureCount() else 0
points = [endPoint]
for current, f in enumerate(features):
if feedback.isCanceled():
break
points.append(f.geometry().asPoint())
feedback.setProgress(int(current * total))
feedback.pushInfo(self.tr('Building graph...'))
snappedPoints = director.makeGraph(builder, points, feedback)
feedback.pushInfo(self.tr('Calculating shortest paths...'))
graph = builder.graph()
idxEnd = graph.findVertex(snappedPoints[0])
route = []
nPoints = len(snappedPoints)
total = 100.0 / nPoints if nPoints else 1
for i in range(1, count + 1):
if feedback.isCanceled():
break
idxStart = graph.findVertex(snappedPoints[i])
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
if tree[idxEnd] == -1:
msg = self.tr('There is no route from start point ({}) to end point ({}).'.format(points[i].toString(), endPoint.toString()))
feedback.setProgressText(msg)
QgsMessageLog.logMessage(msg, self.tr('Processing'), QgsMessageLog.WARNING)
continue
cost = 0.0
current = idxEnd
while current != idxStart:
cost += graph.edge(tree[current]).cost(0)
route.append(graph.vertex(graph.edge(tree[current]).inVertex()).point())
current = graph.edge(tree[current]).outVertex()
#.........这里部分代码省略.........
示例4: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
if network is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
startPoint = self.parameterAsPoint(parameters, self.START_POINT, context, network.sourceCrs())
endPoint = self.parameterAsPoint(parameters, self.END_POINT, context, network.sourceCrs())
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
fields = QgsFields()
fields.append(QgsField('start', QVariant.String, '', 254, 0))
fields.append(QgsField('end', QVariant.String, '', 254, 0))
fields.append(QgsField('cost', QVariant.Double, '', 20, 7))
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.LineString, network.sourceCrs())
if sink is None:
raise QgsProcessingException(self.invalidSinkError(parameters, self.OUTPUT))
directionField = -1
if directionField:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
multiplier = 3600
director.addStrategy(strategy)
builder = QgsGraphBuilder(network.sourceCrs(),
True,
tolerance)
feedback.pushInfo(QCoreApplication.translate('ShortestPathPointToPoint', 'Building graph…'))
snappedPoints = director.makeGraph(builder, [startPoint, endPoint], feedback)
feedback.pushInfo(QCoreApplication.translate('ShortestPathPointToPoint', 'Calculating shortest path…'))
graph = builder.graph()
idxStart = graph.findVertex(snappedPoints[0])
idxEnd = graph.findVertex(snappedPoints[1])
tree, costs = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
if tree[idxEnd] == -1:
raise QgsProcessingException(
self.tr('There is no route from start point to end point.'))
route = [graph.vertex(idxEnd).point()]
cost = costs[idxEnd]
current = idxEnd
while current != idxStart:
current = graph.edge(tree[current]).fromVertex()
route.append(graph.vertex(current).point())
route.reverse()
feedback.pushInfo(QCoreApplication.translate('ShortestPathPointToPoint', 'Writing results…'))
geom = QgsGeometry.fromPolylineXY(route)
feat = QgsFeature()
feat.setFields(fields)
feat['start'] = startPoint.toString()
feat['end'] = endPoint.toString()
feat['cost'] = cost / multiplier
feat.setGeometry(geom)
sink.addFeature(feat, QgsFeatureSink.FastInsert)
results = {}
results[self.TRAVEL_COST] = cost / multiplier
results[self.OUTPUT] = dest_id
return results示例5: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
startPoints = self.parameterAsSource(parameters, self.START_POINTS, context)
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
travelCost = self.parameterAsDouble(parameters, self.TRAVEL_COST, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
fields = startPoints.fields()
fields.append(QgsField('type', QVariant.String, '', 254, 0))
fields.append(QgsField('start', QVariant.String, '', 254, 0))
feat = QgsFeature()
feat.setFields(fields)
directionField = -1
if directionFieldName:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
director.addStrategy(strategy)
builder = QgsGraphBuilder(network.sourceCrs(),
True,
tolerance)
feedback.pushInfo(self.tr('Loading start points...'))
request = QgsFeatureRequest()
request.setDestinationCrs(network.sourceCrs())
features = startPoints.getFeatures(request)
total = 100.0 / startPoints.featureCount() if startPoints.featureCount() else 0
points = []
source_attributes = {}
i = 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
if not f.hasGeometry():
continue
for p in f.geometry().vertices():
points.append(QgsPointXY(p))
source_attributes[i] = f.attributes()
i += 1
feedback.setProgress(int(current * total))
feedback.pushInfo(self.tr('Building graph...'))
snappedPoints = director.makeGraph(builder, points, feedback)
feedback.pushInfo(self.tr('Calculating service areas...'))
graph = builder.graph()
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.MultiPoint, network.sourceCrs())
vertices = []
upperBoundary = []
lowerBoundary = []
total = 100.0 / len(snappedPoints) if snappedPoints else 1
for i, p in enumerate(snappedPoints):
if feedback.isCanceled():
break
idxStart = graph.findVertex(snappedPoints[i])
origPoint = points[i].toString()
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
for j, v in enumerate(cost):
if v > travelCost and tree[j] != -1:
vertexId = graph.edge(tree[j]).fromVertex()
if cost[vertexId] <= travelCost:
vertices.append(j)
#.........这里部分代码省略.........
示例6: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
network = self.parameterAsSource(parameters, self.INPUT, context)
startPoint = self.parameterAsPoint(parameters, self.START_POINT, context, network.sourceCrs())
strategy = self.parameterAsEnum(parameters, self.STRATEGY, context)
travelCost = self.parameterAsDouble(parameters, self.TRAVEL_COST, context)
directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context)
forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context)
backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context)
bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context)
defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context)
speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context)
defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context)
tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
directionField = -1
if directionFieldName:
directionField = network.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
speedField = network.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(network,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = context.project().crs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
director.addStrategy(strategy)
builder = QgsGraphBuilder(network.sourceCrs(),
True,
tolerance)
feedback.pushInfo(self.tr('Building graph...'))
snappedPoints = director.makeGraph(builder, [startPoint], feedback)
feedback.pushInfo(self.tr('Calculating service area...'))
graph = builder.graph()
idxStart = graph.findVertex(snappedPoints[0])
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
vertices = []
for i, v in enumerate(cost):
if v > travelCost and tree[i] != -1:
vertexId = graph.edge(tree[i]).fromVertex()
if cost[vertexId] <= travelCost:
vertices.append(i)
upperBoundary = []
lowerBoundary = []
for i in vertices:
upperBoundary.append(graph.vertex(graph.edge(tree[i]).toVertex()).point())
lowerBoundary.append(graph.vertex(graph.edge(tree[i]).fromVertex()).point())
feedback.pushInfo(self.tr('Writing results...'))
fields = QgsFields()
fields.append(QgsField('type', QVariant.String, '', 254, 0))
fields.append(QgsField('start', QVariant.String, '', 254, 0))
feat = QgsFeature()
feat.setFields(fields)
geomUpper = QgsGeometry.fromMultiPointXY(upperBoundary)
geomLower = QgsGeometry.fromMultiPointXY(lowerBoundary)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.MultiPoint, network.sourceCrs())
feat.setGeometry(geomUpper)
feat['type'] = 'upper'
feat['start'] = startPoint.toString()
sink.addFeature(feat, QgsFeatureSink.FastInsert)
feat.setGeometry(geomLower)
feat['type'] = 'lower'
feat['start'] = startPoint.toString()
sink.addFeature(feat, QgsFeatureSink.FastInsert)
upperBoundary.append(startPoint)
lowerBoundary.append(startPoint)
geomUpper = QgsGeometry.fromMultiPointXY(upperBoundary)
geomLower = QgsGeometry.fromMultiPointXY(lowerBoundary)
return {self.OUTPUT: dest_id}示例7: processAlgorithm
def processAlgorithm(self, feedback):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_VECTOR))
startPoints = dataobjects.getObjectFromUri(
self.getParameterValue(self.START_POINTS))
strategy = self.getParameterValue(self.STRATEGY)
travelCost = self.getParameterValue(self.TRAVEL_COST)
directionFieldName = self.getParameterValue(self.DIRECTION_FIELD)
forwardValue = self.getParameterValue(self.VALUE_FORWARD)
backwardValue = self.getParameterValue(self.VALUE_BACKWARD)
bothValue = self.getParameterValue(self.VALUE_BOTH)
defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION)
bothValue = self.getParameterValue(self.VALUE_BOTH)
defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION)
speedFieldName = self.getParameterValue(self.SPEED_FIELD)
defaultSpeed = self.getParameterValue(self.DEFAULT_SPEED)
tolerance = self.getParameterValue(self.TOLERANCE)
fields = QgsFields()
fields.append(QgsField('type', QVariant.String, '', 254, 0))
fields.append(QgsField('start', QVariant.String, '', 254, 0))
feat = QgsFeature()
feat.setFields(fields)
writerPoints = self.getOutputFromName(
self.OUTPUT_POINTS).getVectorWriter(
fields,
QgsWkbTypes.MultiPoint,
layer.crs())
writerPolygons = self.getOutputFromName(
self.OUTPUT_POLYGON).getVectorWriter(
fields,
QgsWkbTypes.Polygon,
layer.crs())
directionField = -1
if directionFieldName is not None:
directionField = layer.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName is not None:
speedField = layer.fields().lookupField(speedFieldName)
director = QgsVectorLayerDirector(layer,
directionField,
forwardValue,
backwardValue,
bothValue,
defaultDirection)
distUnit = iface.mapCanvas().mapSettings().destinationCrs().mapUnits()
multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters)
if strategy == 0:
strategy = QgsNetworkDistanceStrategy()
else:
strategy = QgsNetworkSpeedStrategy(speedField,
defaultSpeed,
multiplier * 1000.0 / 3600.0)
director.addStrategy(strategy)
builder = QgsGraphBuilder(iface.mapCanvas().mapSettings().destinationCrs(),
iface.mapCanvas().hasCrsTransformEnabled(),
tolerance)
feedback.pushInfo(self.tr('Loading start points...'))
request = QgsFeatureRequest()
request.setFlags(request.flags() ^ QgsFeatureRequest.SubsetOfAttributes)
features = vector.features(startPoints, request)
points = []
for f in features:
points.append(f.geometry().asPoint())
feedback.pushInfo(self.tr('Building graph...'))
snappedPoints = director.makeGraph(builder, points)
feedback.pushInfo(self.tr('Calculating service areas...'))
graph = builder.graph()
vertices = []
upperBoundary = []
lowerBoundary = []
total = 100.0 / len(snappedPoints)
for i, p in enumerate(snappedPoints):
idxStart = graph.findVertex(snappedPoints[i])
origPoint = points[i].toString()
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
for j, v in enumerate(cost):
if v > travelCost and tree[j] != -1:
vertexId = graph.edge(tree[j]).outVertex()
if cost[vertexId] <= travelCost:
vertices.append(j)
for j in vertices:
upperBoundary.append(graph.vertex(graph.edge(tree[j]).inVertex()).point())
lowerBoundary.append(graph.vertex(graph.edge(tree[j]).outVertex()).point())
geomUpper = QgsGeometry.fromMultiPoint(upperBoundary)
#.........这里部分代码省略.........