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| 1 | +# -*- coding: utf-8 -*- |
| 2 | + |
| 3 | +""" |
| 4 | +*************************************************************************** |
| 5 | + ServiceArea.py |
| 6 | + --------------------- |
| 7 | + Date : December 2016 |
| 8 | + Copyright : (C) 2016 by Alexander Bruy |
| 9 | + Email : alexander dot bruy at gmail dot com |
| 10 | +*************************************************************************** |
| 11 | +* * |
| 12 | +* This program is free software; you can redistribute it and/or modify * |
| 13 | +* it under the terms of the GNU General Public License as published by * |
| 14 | +* the Free Software Foundation; either version 2 of the License, or * |
| 15 | +* (at your option) any later version. * |
| 16 | +* * |
| 17 | +*************************************************************************** |
| 18 | +""" |
| 19 | + |
| 20 | +__author__ = 'Alexander Bruy' |
| 21 | +__date__ = 'December 2016' |
| 22 | +__copyright__ = '(C) 2016, Alexander Bruy' |
| 23 | + |
| 24 | +# This will get replaced with a git SHA1 when you do a git archive |
| 25 | + |
| 26 | +__revision__ = '$Format:%H$' |
| 27 | + |
| 28 | +import os |
| 29 | + |
| 30 | +from qgis.PyQt.QtCore import QVariant |
| 31 | +from qgis.PyQt.QtGui import QIcon |
| 32 | + |
| 33 | +from qgis.core import QgsWkbTypes, QgsUnitTypes, QgsFeature, QgsGeometry, QgsPoint, QgsField, QgsFields |
| 34 | +from qgis.analysis import (QgsVectorLayerDirector, |
| 35 | + QgsNetworkDistanceStrategy, |
| 36 | + QgsNetworkSpeedStrategy, |
| 37 | + QgsGraphBuilder, |
| 38 | + QgsGraphAnalyzer |
| 39 | + ) |
| 40 | +from qgis.utils import iface |
| 41 | + |
| 42 | +from processing.core.GeoAlgorithm import GeoAlgorithm |
| 43 | +from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException |
| 44 | +from processing.core.parameters import (ParameterVector, |
| 45 | + ParameterPoint, |
| 46 | + ParameterNumber, |
| 47 | + ParameterString, |
| 48 | + ParameterTableField, |
| 49 | + ParameterSelection |
| 50 | + ) |
| 51 | +from processing.core.outputs import (OutputNumber, |
| 52 | + OutputVector |
| 53 | + ) |
| 54 | +from processing.tools import dataobjects |
| 55 | + |
| 56 | +pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] |
| 57 | + |
| 58 | + |
| 59 | +class ServiceArea(GeoAlgorithm): |
| 60 | + |
| 61 | + INPUT_VECTOR = 'INPUT_VECTOR' |
| 62 | + START_POINT = 'START_POINT' |
| 63 | + STRATEGY = 'STRATEGY' |
| 64 | + TRAVEL_COST = 'TRAVEL_COST' |
| 65 | + DIRECTION_FIELD = 'DIRECTION_FIELD' |
| 66 | + VALUE_FORWARD = 'VALUE_FORWARD' |
| 67 | + VALUE_BACKWARD = 'VALUE_BACKWARD' |
| 68 | + VALUE_BOTH = 'VALUE_BOTH' |
| 69 | + DEFAULT_DIRECTION = 'DEFAULT_DIRECTION' |
| 70 | + SPEED_FIELD = 'SPEED_FIELD' |
| 71 | + DEFAULT_SPEED = 'DEFAULT_SPEED' |
| 72 | + TOLERANCE = 'TOLERANCE' |
| 73 | + OUTPUT_LAYER = 'OUTPUT_LAYER' |
| 74 | + |
| 75 | + def getIcon(self): |
| 76 | + return QIcon(os.path.join(pluginPath, 'images', 'networkanalysis.svg')) |
| 77 | + |
| 78 | + def defineCharacteristics(self): |
| 79 | + self.DIRECTIONS = {self.tr('Forward direction'): QgsVectorLayerDirector.DirectionForward, |
| 80 | + self.tr('Backward direction'): QgsVectorLayerDirector.DirectionForward, |
| 81 | + self.tr('Both directions'): QgsVectorLayerDirector.DirectionForward |
| 82 | + } |
| 83 | + |
| 84 | + self.STRATEGIES = [self.tr('Shortest'), |
| 85 | + self.tr('Fastest') |
| 86 | + ] |
| 87 | + |
| 88 | + self.name, self.i18n_name = self.trAlgorithm('Service area') |
| 89 | + self.group, self.i18n_group = self.trAlgorithm('Network analysis') |
| 90 | + |
| 91 | + self.addParameter(ParameterVector(self.INPUT_VECTOR, |
| 92 | + self.tr('Vector layer representing network'), |
| 93 | + [dataobjects.TYPE_VECTOR_LINE])) |
| 94 | + self.addParameter(ParameterPoint(self.START_POINT, |
| 95 | + self.tr('Start point'))) |
| 96 | + self.addParameter(ParameterSelection(self.STRATEGY, |
| 97 | + self.tr('Path type to calculate'), |
| 98 | + self.STRATEGIES, |
| 99 | + default=0)) |
| 100 | + self.addParameter(ParameterNumber(self.TRAVEL_COST, |
| 101 | + self.tr('Travel cost (distance for "Shortest", time for "Fastest")'), |
| 102 | + 0.0, 99999999.999999, 0.0)) |
| 103 | + |
| 104 | + params = [] |
| 105 | + params.append(ParameterTableField(self.DIRECTION_FIELD, |
| 106 | + self.tr('Direction field'), |
| 107 | + self.INPUT_VECTOR, |
| 108 | + optional=True)) |
| 109 | + params.append(ParameterString(self.VALUE_FORWARD, |
| 110 | + self.tr('Value for forward direction'), |
| 111 | + '', |
| 112 | + optional=True)) |
| 113 | + params.append(ParameterString(self.VALUE_BACKWARD, |
| 114 | + self.tr('Value for backward direction'), |
| 115 | + '', |
| 116 | + optional=True)) |
| 117 | + params.append(ParameterString(self.VALUE_BOTH, |
| 118 | + self.tr('Value for both directions'), |
| 119 | + '', |
| 120 | + optional=True)) |
| 121 | + params.append(ParameterSelection(self.DEFAULT_DIRECTION, |
| 122 | + self.tr('Default direction'), |
| 123 | + list(self.DIRECTIONS.keys()), |
| 124 | + default=0)) |
| 125 | + params.append(ParameterTableField(self.SPEED_FIELD, |
| 126 | + self.tr('Speed field'), |
| 127 | + self.INPUT_VECTOR, |
| 128 | + optional=True)) |
| 129 | + params.append(ParameterNumber(self.DEFAULT_SPEED, |
| 130 | + self.tr('Default speed (km/h)'), |
| 131 | + 0.0, 99999999.999999, 5.0)) |
| 132 | + params.append(ParameterNumber(self.TOLERANCE, |
| 133 | + self.tr('Topology tolerance'), |
| 134 | + 0.0, 99999999.999999, 0.0)) |
| 135 | + |
| 136 | + for p in params: |
| 137 | + p.isAdvanced = True |
| 138 | + self.addParameter(p) |
| 139 | + |
| 140 | + self.addOutput(OutputVector(self.OUTPUT_LAYER, |
| 141 | + self.tr('Service area'), |
| 142 | + datatype=[dataobjects.TYPE_VECTOR_POLYGON])) |
| 143 | + |
| 144 | + def processAlgorithm(self, progress): |
| 145 | + layer = dataobjects.getObjectFromUri( |
| 146 | + self.getParameterValue(self.INPUT_VECTOR)) |
| 147 | + startPoint = self.getParameterValue(self.START_POINT) |
| 148 | + strategy = self.getParameterValue(self.STRATEGY) |
| 149 | + travelCost = self.getParameterValue(self.TRAVEL_COST) |
| 150 | + |
| 151 | + directionFieldName = self.getParameterValue(self.DIRECTION_FIELD) |
| 152 | + forwardValue = self.getParameterValue(self.VALUE_FORWARD) |
| 153 | + backwardValue = self.getParameterValue(self.VALUE_BACKWARD) |
| 154 | + bothValue = self.getParameterValue(self.VALUE_BOTH) |
| 155 | + defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION) |
| 156 | + bothValue = self.getParameterValue(self.VALUE_BOTH) |
| 157 | + defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION) |
| 158 | + speedFieldName = self.getParameterValue(self.SPEED_FIELD) |
| 159 | + defaultSpeed = self.getParameterValue(self.DEFAULT_SPEED) |
| 160 | + tolerance = self.getParameterValue(self.TOLERANCE) |
| 161 | + |
| 162 | + fields = QgsFields() |
| 163 | + fields.append(QgsField('type', QVariant.String, '', 254, 0)) |
| 164 | + writer = self.getOutputFromName( |
| 165 | + self.OUTPUT_LAYER).getVectorWriter( |
| 166 | + fields, |
| 167 | + QgsWkbTypes.Polygon, |
| 168 | + layer.crs()) |
| 169 | + |
| 170 | + tmp = startPoint.split(',') |
| 171 | + startPoint = QgsPoint(float(tmp[0]), float(tmp[1])) |
| 172 | + |
| 173 | + directionField = -1 |
| 174 | + if directionFieldName is not None: |
| 175 | + directionField = layer.fields().lookupField(directionFieldName) |
| 176 | + speedField = -1 |
| 177 | + if speedFieldName is not None: |
| 178 | + speedField = layer.fields().lookupField(speedFieldName) |
| 179 | + |
| 180 | + director = QgsVectorLayerDirector(layer, |
| 181 | + directionField, |
| 182 | + forwardValue, |
| 183 | + backwardValue, |
| 184 | + bothValue, |
| 185 | + defaultDirection) |
| 186 | + |
| 187 | + distUnit = iface.mapCanvas().mapSettings().destinationCrs().mapUnits() |
| 188 | + multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters) |
| 189 | + if strategy == 0: |
| 190 | + strategy = QgsNetworkDistanceStrategy() |
| 191 | + else: |
| 192 | + strategy = QgsNetworkSpeedStrategy(speedField, |
| 193 | + defaultSpeed, |
| 194 | + multiplier * 1000.0 / 3600.0) |
| 195 | + |
| 196 | + director.addStrategy(strategy) |
| 197 | + builder = QgsGraphBuilder(iface.mapCanvas().mapSettings().destinationCrs(), |
| 198 | + iface.mapCanvas().hasCrsTransformEnabled(), |
| 199 | + tolerance) |
| 200 | + progress.setInfo(self.tr('Building graph...')) |
| 201 | + snappedPoints = director.makeGraph(builder, [startPoint]) |
| 202 | + |
| 203 | + progress.setInfo(self.tr('Calculating service area...')) |
| 204 | + graph = builder.graph() |
| 205 | + idxStart = graph.findVertex(snappedPoints[0]) |
| 206 | + |
| 207 | + tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0) |
| 208 | + vertices = [] |
| 209 | + for i, v in enumerate(cost): |
| 210 | + if v > travelCost and tree[i] != -1: |
| 211 | + vertexId = graph.edge(tree [i]).outVertex() |
| 212 | + if cost[vertexId] <= travelCost: |
| 213 | + vertices.append(i) |
| 214 | + |
| 215 | + upperBoundary = [] |
| 216 | + lowerBoundary = [] |
| 217 | + for i in vertices: |
| 218 | + upperBoundary.append(graph.vertex(graph.edge(tree[i]).inVertex()).point()) |
| 219 | + lowerBoundary.append(graph.vertex(graph.edge(tree[i]).outVertex()).point()) |
| 220 | + |
| 221 | + progress.setInfo(self.tr('Writting results...')) |
| 222 | + feat = QgsFeature() |
| 223 | + feat.setFields(fields) |
| 224 | + |
| 225 | + geom = QgsGeometry.fromMultiPoint(upperBoundary) |
| 226 | + geom = geom.convexHull() |
| 227 | + feat.setGeometry(geom) |
| 228 | + feat['type'] = 'upper' |
| 229 | + writer.addFeature(feat) |
| 230 | + |
| 231 | + geom = QgsGeometry.fromMultiPoint(lowerBoundary) |
| 232 | + geom = geom.convexHull() |
| 233 | + feat.setGeometry(geom) |
| 234 | + feat['type'] = 'lower' |
| 235 | + writer.addFeature(feat) |
| 236 | + del writer |
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