# -*- coding: utf-8 -*- """ *************************************************************************** ServiceAreaFromLayer.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, QgsGeometry, QgsPoint, QgsField, QgsFields, QgsFeatureRequest from qgis.analysis import (QgsVectorLayerDirector, QgsNetworkDistanceStrategy, QgsNetworkSpeedStrategy, QgsGraphBuilder, QgsGraphAnalyzer ) from qgis.utils import iface from processing.core.GeoAlgorithm import GeoAlgorithm from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException from processing.core.parameters import (ParameterVector, ParameterNumber, ParameterString, ParameterTableField, ParameterSelection ) from processing.core.outputs import (OutputNumber, OutputVector ) from processing.tools import dataobjects, vector pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class ServiceAreaFromLayer(GeoAlgorithm): INPUT_VECTOR = 'INPUT_VECTOR' START_POINTS = 'START_POINTS' 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_POINTS = 'OUTPUT_POINTS' OUTPUT_POLYGON = 'OUTPUT_POLYGON' def getIcon(self): return QIcon(os.path.join(pluginPath, 'images', 'networkanalysis.svg')) def defineCharacteristics(self): self.DIRECTIONS = OrderedDict([ (self.tr('Forward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Backward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Both directions'), QgsVectorLayerDirector.DirectionForward)]) self.STRATEGIES = [self.tr('Shortest'), self.tr('Fastest') ] self.name, self.i18n_name = self.trAlgorithm('Service area (from layer)') self.group, self.i18n_group = self.trAlgorithm('Network analysis') self.addParameter(ParameterVector(self.INPUT_VECTOR, self.tr('Vector layer representing network'), [dataobjects.TYPE_VECTOR_LINE])) self.addParameter(ParameterVector(self.START_POINTS, self.tr('Vector layer with start points'), [dataobjects.TYPE_VECTOR_POINT])) self.addParameter(ParameterSelection(self.STRATEGY, self.tr('Path type to calculate'), self.STRATEGIES, default=0)) self.addParameter(ParameterNumber(self.TRAVEL_COST, self.tr('Travel cost (distance for "Shortest", time for "Fastest")'), 0.0, 99999999.999999, 0.0)) params = [] params.append(ParameterTableField(self.DIRECTION_FIELD, self.tr('Direction field'), self.INPUT_VECTOR, optional=True)) params.append(ParameterString(self.VALUE_FORWARD, self.tr('Value for forward direction'), '', optional=True)) params.append(ParameterString(self.VALUE_BACKWARD, self.tr('Value for backward direction'), '', optional=True)) params.append(ParameterString(self.VALUE_BOTH, self.tr('Value for both directions'), '', optional=True)) params.append(ParameterSelection(self.DEFAULT_DIRECTION, self.tr('Default direction'), list(self.DIRECTIONS.keys()), default=2)) params.append(ParameterTableField(self.SPEED_FIELD, self.tr('Speed field'), self.INPUT_VECTOR, optional=True)) params.append(ParameterNumber(self.DEFAULT_SPEED, self.tr('Default speed (km/h)'), 0.0, 99999999.999999, 5.0)) params.append(ParameterNumber(self.TOLERANCE, self.tr('Topology tolerance'), 0.0, 99999999.999999, 0.0)) for p in params: p.isAdvanced = True self.addParameter(p) self.addOutput(OutputVector(self.OUTPUT_POINTS, self.tr('Service area (boundary nodes)'), datatype=[dataobjects.TYPE_VECTOR_POINT])) self.addOutput(OutputVector(self.OUTPUT_POLYGON, self.tr('Service area (convex hull)'), datatype=[dataobjects.TYPE_VECTOR_POLYGON])) 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) geomLower = QgsGeometry.fromMultiPoint(lowerBoundary) feat.setGeometry(geomUpper) feat['type'] = 'upper' feat['start'] = origPoint writerPoints.addFeature(feat) feat.setGeometry(geomLower) feat['type'] = 'lower' feat['start'] = origPoint writerPoints.addFeature(feat) upperBoundary.append(startPoint) lowerBoundary.append(startPoint) geomUpper = QgsGeometry.fromMultiPoint(upperBoundary) geomLower = QgsGeometry.fromMultiPoint(lowerBoundary) geom = geomUpper.convexHull() feat.setGeometry(geom) feat['type'] = 'upper' feat['start'] = origPoint writerPolygons.addFeature(feat) geom = geomLower.convexHull() feat.setGeometry(geom) feat['type'] = 'lower' feat['start'] = origPoint writerPolygons.addFeature(feat) vertices[:] = [] upperBoundary[:] = [] lowerBoundary[:] = [] feedback.setProgress(int(i * total)) del writerPoints del writerPolygons