mirror of
https://github.com/qgis/QGIS.git
synced 2025-03-03 00:02:25 -05:00
c4f3832af2
and add new QgsGeometry::fromPolyline which uses QgsPoint We want to encourage people not to use the QgsPointXY method, as it drops Z/M values. So it's moved across to a different name to make way for a new QgsGeometry::fromPolyline which uses a QgsPoint list instead of QgsPointXY, thus keeping Z/M values intact. Similarly, QgsPolyline now is a list of QgsPoint (keeping z/m values) and the old 2d QgsPolyline type was renamed to QgsPolylineXY. Making the QgsPoint method the "preferred" method and making linestrings just as easy to create from z/m dimensioned points as 2d points is important to push people to write code which does not discard these important dimensions. As a bonus, the QgsPoint methods are more efficient anyway, since they don't require creation of a temporary list.
250 lines
12 KiB
Python
250 lines
12 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
ShortestPathPointToPoint.py
|
|
---------------------
|
|
Date : November 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__ = 'November 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,
|
|
QgsProcessingException,
|
|
QgsProcessingOutputNumber,
|
|
QgsProcessingParameterEnum,
|
|
QgsProcessingParameterPoint,
|
|
QgsProcessingParameterField,
|
|
QgsProcessingParameterNumber,
|
|
QgsProcessingParameterString,
|
|
QgsProcessingParameterFeatureSource,
|
|
QgsProcessingParameterFeatureSink,
|
|
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 ShortestPathPointToPoint(QgisAlgorithm):
|
|
|
|
INPUT = 'INPUT'
|
|
START_POINT = 'START_POINT'
|
|
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'
|
|
TRAVEL_COST = 'TRAVEL_COST'
|
|
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(QgsProcessingParameterFeatureSource(self.INPUT,
|
|
self.tr('Vector layer representing network'),
|
|
[QgsProcessing.TypeVectorLine]))
|
|
self.addParameter(QgsProcessingParameterPoint(self.START_POINT,
|
|
self.tr('Start point')))
|
|
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.addOutput(QgsProcessingOutputNumber(self.TRAVEL_COST,
|
|
self.tr('Travel cost')))
|
|
self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT,
|
|
self.tr('Shortest path'),
|
|
QgsProcessing.TypeVectorLine))
|
|
|
|
def name(self):
|
|
return 'shortestpathpointtopoint'
|
|
|
|
def displayName(self):
|
|
return self.tr('Shortest path (point to point)')
|
|
|
|
def processAlgorithm(self, parameters, context, feedback):
|
|
network = self.parameterAsSource(parameters, self.INPUT, context)
|
|
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())
|
|
|
|
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(self.tr('Building graph...'))
|
|
snappedPoints = director.makeGraph(builder, [startPoint, endPoint], feedback)
|
|
|
|
feedback.pushInfo(self.tr('Calculating shortest path...'))
|
|
graph = builder.graph()
|
|
idxStart = graph.findVertex(snappedPoints[0])
|
|
idxEnd = graph.findVertex(snappedPoints[1])
|
|
|
|
tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0)
|
|
if tree[idxEnd] == -1:
|
|
raise QgsProcessingException(
|
|
self.tr('There is no route from start point to end point.'))
|
|
|
|
route = []
|
|
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[0])
|
|
route.reverse()
|
|
|
|
feedback.pushInfo(self.tr('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
|