# -*- coding: utf-8 -*- """ *************************************************************************** ServiceAreaFromPoint.py --------------------- Date : December 2016 Copyright : (C) 2016 by Alexander Bruy Email : alexander dot bruy at gmail dot com *************************************************************************** * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * *************************************************************************** """ __author__ = 'Alexander Bruy' __date__ = 'December 2016' __copyright__ = '(C) 2016, Alexander Bruy' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import os from collections import OrderedDict from qgis.PyQt.QtCore import QVariant from qgis.PyQt.QtGui import QIcon from qgis.core import (QgsWkbTypes, QgsUnitTypes, QgsFeature, QgsFeatureSink, QgsGeometry, QgsFields, QgsField, QgsProcessing, QgsProcessingParameterEnum, QgsProcessingParameterPoint, QgsProcessingParameterField, QgsProcessingParameterNumber, QgsProcessingParameterString, QgsProcessingParameterFeatureSink, QgsProcessingParameterFeatureSource, QgsProcessingParameterDefinition) from qgis.analysis import (QgsVectorLayerDirector, QgsNetworkDistanceStrategy, QgsNetworkSpeedStrategy, QgsGraphBuilder, QgsGraphAnalyzer ) from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class ServiceAreaFromPoint(QgisAlgorithm): INPUT = 'INPUT' START_POINT = 'START_POINT' STRATEGY = 'STRATEGY' TRAVEL_COST = 'TRAVEL_COST' DIRECTION_FIELD = 'DIRECTION_FIELD' VALUE_FORWARD = 'VALUE_FORWARD' VALUE_BACKWARD = 'VALUE_BACKWARD' VALUE_BOTH = 'VALUE_BOTH' DEFAULT_DIRECTION = 'DEFAULT_DIRECTION' SPEED_FIELD = 'SPEED_FIELD' DEFAULT_SPEED = 'DEFAULT_SPEED' TOLERANCE = 'TOLERANCE' OUTPUT = 'OUTPUT' def icon(self): return QIcon(os.path.join(pluginPath, 'images', 'networkanalysis.svg')) def group(self): return self.tr('Network analysis') def __init__(self): super().__init__() def initAlgorithm(self, config=None): self.DIRECTIONS = OrderedDict([ (self.tr('Forward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Backward direction'), QgsVectorLayerDirector.DirectionBackward), (self.tr('Both directions'), QgsVectorLayerDirector.DirectionBoth)]) self.STRATEGIES = [self.tr('Shortest'), self.tr('Fastest') ] self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Vector layer representing network'), [QgsProcessing.TypeVectorLine])) self.addParameter(QgsProcessingParameterPoint(self.START_POINT, self.tr('Start point'))) self.addParameter(QgsProcessingParameterEnum(self.STRATEGY, self.tr('Path type to calculate'), self.STRATEGIES, defaultValue=0)) self.addParameter(QgsProcessingParameterNumber(self.TRAVEL_COST, self.tr('Travel cost (distance for "Shortest", time for "Fastest")'), QgsProcessingParameterNumber.Double, 0.0, False, 0, 99999999.99)) params = [] params.append(QgsProcessingParameterField(self.DIRECTION_FIELD, self.tr('Direction field'), None, self.INPUT, optional=True)) params.append(QgsProcessingParameterString(self.VALUE_FORWARD, self.tr('Value for forward direction'), optional=True)) params.append(QgsProcessingParameterString(self.VALUE_BACKWARD, self.tr('Value for backward direction'), optional=True)) params.append(QgsProcessingParameterString(self.VALUE_BOTH, self.tr('Value for both directions'), optional=True)) params.append(QgsProcessingParameterEnum(self.DEFAULT_DIRECTION, self.tr('Default direction'), list(self.DIRECTIONS.keys()), defaultValue=2)) params.append(QgsProcessingParameterField(self.SPEED_FIELD, self.tr('Speed field'), None, self.INPUT, optional=True)) params.append(QgsProcessingParameterNumber(self.DEFAULT_SPEED, self.tr('Default speed (km/h)'), QgsProcessingParameterNumber.Double, 5.0, False, 0, 99999999.99)) params.append(QgsProcessingParameterNumber(self.TOLERANCE, self.tr('Topology tolerance'), QgsProcessingParameterNumber.Double, 0.0, False, 0, 99999999.99)) for p in params: p.setFlags(p.flags() | QgsProcessingParameterDefinition.FlagAdvanced) self.addParameter(p) self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Service area (boundary nodes)'), QgsProcessing.TypeVectorPoint)) def name(self): return 'serviceareafrompoint' def displayName(self): return self.tr('Service area (from point)') 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}