QGIS/python/plugins/processing/algs/qgis/HubDistanceLines.py
Nyall Dawson 427c3b1684 Remove vector.features
Use QgsProcessingUtils.getFeatures instead
2017-04-26 12:53:35 +10:00

159 lines
6.0 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
HubDistanceLines.py
---------------------
Date : May 2010
Copyright : (C) 2010 by Michael Minn
Email : pyqgis at michaelminn 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. *
* *
***************************************************************************
"""
from builtins import next
__author__ = 'Michael Minn'
__date__ = 'May 2010'
__copyright__ = '(C) 2010, Michael Minn'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from qgis.PyQt.QtCore import QVariant
from qgis.core import (QgsField,
QgsGeometry,
QgsDistanceArea,
QgsFeature,
QgsFeatureRequest,
QgsWkbTypes,
QgsApplication,
QgsProject,
QgsProcessingUtils)
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterTableField
from processing.core.parameters import ParameterSelection
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
from math import sqrt
class HubDistanceLines(GeoAlgorithm):
POINTS = 'POINTS'
HUBS = 'HUBS'
FIELD = 'FIELD'
UNIT = 'UNIT'
OUTPUT = 'OUTPUT'
UNITS = ['Meters',
'Feet',
'Miles',
'Kilometers',
'Layer units'
]
def icon(self):
return QgsApplication.getThemeIcon("/providerQgis.svg")
def svgIconPath(self):
return QgsApplication.iconPath("providerQgis.svg")
def group(self):
return self.tr('Vector analysis tools')
def name(self):
return 'distancetonearesthublinetohub'
def displayName(self):
return self.tr('Distance to nearest hub (line to hub)')
def defineCharacteristics(self):
self.units = [self.tr('Meters'),
self.tr('Feet'),
self.tr('Miles'),
self.tr('Kilometers'),
self.tr('Layer units')]
self.addParameter(ParameterVector(self.POINTS,
self.tr('Source points layer')))
self.addParameter(ParameterVector(self.HUBS,
self.tr('Destination hubs layer')))
self.addParameter(ParameterTableField(self.FIELD,
self.tr('Hub layer name attribute'), self.HUBS))
self.addParameter(ParameterSelection(self.UNIT,
self.tr('Measurement unit'), self.units))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Hub distance'), datatype=[dataobjects.TYPE_VECTOR_LINE]))
def processAlgorithm(self, context, feedback):
layerPoints = dataobjects.getLayerFromString(
self.getParameterValue(self.POINTS))
layerHubs = dataobjects.getLayerFromString(
self.getParameterValue(self.HUBS))
fieldName = self.getParameterValue(self.FIELD)
units = self.UNITS[self.getParameterValue(self.UNIT)]
if layerPoints.source() == layerHubs.source():
raise GeoAlgorithmExecutionException(
self.tr('Same layer given for both hubs and spokes'))
fields = layerPoints.fields()
fields.append(QgsField('HubName', QVariant.String))
fields.append(QgsField('HubDist', QVariant.Double))
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
fields, QgsWkbTypes.LineString, layerPoints.crs())
index = vector.spatialindex(layerHubs)
distance = QgsDistanceArea()
distance.setSourceCrs(layerPoints.crs())
distance.setEllipsoid(QgsProject.instance().ellipsoid())
# Scan source points, find nearest hub, and write to output file
features = QgsProcessingUtils.getFeatures(layerPoints, context)
total = 100.0 / QgsProcessingUtils.featureCount(layerPoints, context)
for current, f in enumerate(features):
src = f.geometry().boundingBox().center()
neighbors = index.nearestNeighbor(src, 1)
ft = next(layerHubs.getFeatures(QgsFeatureRequest().setFilterFid(neighbors[0]).setSubsetOfAttributes([fieldName], layerHubs.fields())))
closest = ft.geometry().boundingBox().center()
hubDist = distance.measureLine(src, closest)
attributes = f.attributes()
attributes.append(ft[fieldName])
if units == 'Feet':
attributes.append(hubDist * 3.2808399)
elif units == 'Miles':
attributes.append(hubDist * 0.000621371192)
elif units == 'Kilometers':
attributes.append(hubDist / 1000.0)
elif units != 'Meters':
attributes.append(sqrt(
pow(src.x() - closest.x(), 2.0) +
pow(src.y() - closest.y(), 2.0)))
else:
attributes.append(hubDist)
feat = QgsFeature()
feat.setAttributes(attributes)
feat.setGeometry(QgsGeometry.fromPolyline([src, closest]))
writer.addFeature(feat)
feedback.setProgress(int(current * total))
del writer