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118 lines
4.1 KiB
Python
118 lines
4.1 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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Delaunay.py
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---------------------
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Date : August 2012
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Copyright : (C) 2012 by Victor Olaya
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from sets import Set
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from PyQt4.QtCore import *
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from qgis.core import *
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import \
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GeoAlgorithmExecutionException
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from processing.tools import dataobjects, vector
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from processing.core.parameters import ParameterVector
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from processing.core.outputs import OutputVector
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import voronoi
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class Delaunay(GeoAlgorithm):
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INPUT = 'INPUT'
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OUTPUT = 'OUTPUT'
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def defineCharacteristics(self):
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self.name = 'Delaunay triangulation'
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self.group = 'Vector geometry tools'
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self.addParameter(ParameterVector(self.INPUT, 'Input layer',
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[ParameterVector.VECTOR_TYPE_POINT]))
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self.addOutput(OutputVector(self.OUTPUT, 'Delaunay triangulation'))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(
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self.getParameterValue(self.INPUT))
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fields = [QgsField('POINTA', QVariant.Double, '', 24, 15),
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QgsField('POINTB', QVariant.Double, '', 24, 15),
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QgsField('POINTC', QVariant.Double, '', 24, 15)]
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields,
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QGis.WKBPolygon, layer.crs())
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pts = []
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ptDict = {}
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ptNdx = -1
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c = voronoi.Context()
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features = vector.features(layer)
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for inFeat in features:
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geom = QgsGeometry(inFeat.geometry())
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point = geom.asPoint()
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x = point.x()
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y = point.y()
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pts.append((x, y))
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ptNdx += 1
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ptDict[ptNdx] = inFeat.id()
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if len(pts) < 3:
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raise GeoAlgorithmExecutionException(
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'Input file should contain at least 3 points. Choose \
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another file and try again.')
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uniqueSet = Set(item for item in pts)
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ids = [pts.index(item) for item in uniqueSet]
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sl = voronoi.SiteList([voronoi.Site(*i) for i in uniqueSet])
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c.triangulate = True
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voronoi.voronoi(sl, c)
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triangles = c.triangles
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feat = QgsFeature()
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current = 0
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total = 100.0 / float(len(triangles))
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for triangle in triangles:
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indicies = list(triangle)
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indicies.append(indicies[0])
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polygon = []
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attrs = []
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step = 0
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for index in indicies:
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request = QgsFeatureRequest().setFilterFid(ptDict[ids[index]])
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inFeat = layer.getFeatures(request).next()
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geom = QgsGeometry(inFeat.geometry())
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point = QgsPoint(geom.asPoint())
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polygon.append(point)
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if step <= 3:
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attrs.append(ids[index])
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step += 1
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feat.setAttributes(attrs)
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geometry = QgsGeometry().fromPolygon([polygon])
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feat.setGeometry(geometry)
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writer.addFeature(feat)
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current += 1
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progress.setPercentage(int(current * total))
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del writer
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