/
ShortestPathLayerToPoint.py
270 lines (224 loc) · 12.3 KB
/
ShortestPathLayerToPoint.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
# -*- coding: utf-8 -*-
"""
***************************************************************************
ShortestPathLayerToPoint.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,
QgsMessageLog,
QgsProcessing,
QgsProcessingParameterEnum,
QgsProcessingParameterPoint,
QgsProcessingParameterField,
QgsProcessingParameterNumber,
QgsProcessingParameterString,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterFeatureSink,
QgsProcessingParameterVectorLayer,
QgsProcessingParameterDefinition)
from qgis.analysis import (QgsVectorLayerDirector,
QgsNetworkDistanceStrategy,
QgsNetworkSpeedStrategy,
QgsGraphBuilder,
QgsGraphAnalyzer
)
from qgis.utils import iface
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class ShortestPathLayerToPoint(QgisAlgorithm):
INPUT = 'INPUT'
START_POINTS = 'START_POINTS'
END_POINT = 'END_POINT'
STRATEGY = 'STRATEGY'
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.DirectionForward),
(self.tr('Both directions'), QgsVectorLayerDirector.DirectionForward)])
self.STRATEGIES = [self.tr('Shortest'),
self.tr('Fastest')
]
self.addParameter(QgsProcessingParameterVectorLayer(self.INPUT,
self.tr('Vector layer representing network'),
[QgsProcessing.TypeVectorLine]))
self.addParameter(QgsProcessingParameterFeatureSource(self.START_POINTS,
self.tr('Vector layer with start points'),
[QgsProcessing.TypeVectorPoint]))
self.addParameter(QgsProcessingParameterPoint(self.END_POINT,
self.tr('End point')))
self.addParameter(QgsProcessingParameterEnum(self.STRATEGY,
self.tr('Path type to calculate'),
self.STRATEGIES,
defaultValue=0))
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('Shortest path'),
QgsProcessing.TypeVectorLine))
def name(self):
return 'shortestpathlayertopoint'
def displayName(self):
return self.tr('Shortest path (layer to point)')
def processAlgorithm(self, parameters, context, feedback):
layer = self.parameterAsVectorLayer(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, layer.crs())
directionField = -1
if directionFieldName:
directionField = layer.fields().lookupField(directionFieldName)
speedField = -1
if speedFieldName:
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)
multiplier = 3600
director.addStrategy(strategy)
builder = QgsGraphBuilder(iface.mapCanvas().mapSettings().destinationCrs(),
True,
tolerance)
feedback.pushInfo(self.tr('Loading start points...'))
request = QgsFeatureRequest()
request.setFlags(request.flags() ^ QgsFeatureRequest.SubsetOfAttributes)
features = source.getFeatures(request)
total = 100.0 / source.featureCount() if source.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.pushInfo(self.tr('Calculating shortest paths...'))
graph = builder.graph()
idxEnd = graph.findVertex(snappedPoints[0])
route = []
total = 100.0 / source.featureCount() if source.featureCount() else 1
for i in range(1, count + 1):
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()
route.append(snappedPoints[i])
route.reverse()
geom = QgsGeometry.fromPolyline(route)
feat.setGeometry(geom)
feat['start'] = points[i].toString()
feat['end'] = endPoint.toString()
feat['cost'] = cost / multiplier
sink.addFeature(feat, QgsFeatureSink.FastInsert)
route[:] = []
feedback.setProgress(int(i * total))
return {self.OUTPUT: dest_id}