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125 lines
4.7 KiB
Python
125 lines
4.7 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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MeanCoords.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 PyQt4.QtCore import QVariant
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from qgis.core import QGis, QgsField, QgsFeature, QgsGeometry, QgsPoint
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.parameters import ParameterTableField
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from processing.core.parameters import ParameterVector
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects, vector
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class MeanCoords(GeoAlgorithm):
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POINTS = 'POINTS'
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WEIGHT = 'WEIGHT'
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OUTPUT = 'OUTPUT'
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UID = 'UID'
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WEIGHT = 'WEIGHT'
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Mean coordinate(s)')
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self.group, self.i18n_group = self.trAlgorithm('Vector analysis tools')
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self.addParameter(ParameterVector(self.POINTS,
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self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_ANY]))
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self.addParameter(ParameterTableField(self.WEIGHT,
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self.tr('Weight field'), MeanCoords.POINTS,
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ParameterTableField.DATA_TYPE_NUMBER, optional=True))
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self.addParameter(ParameterTableField(self.UID,
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self.tr('Unique ID field'), MeanCoords.POINTS,
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ParameterTableField.DATA_TYPE_NUMBER, optional=True))
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self.addOutput(OutputVector(MeanCoords.OUTPUT, self.tr('Mean coordinates')))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(self.getParameterValue(self.POINTS))
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weightField = self.getParameterValue(self.WEIGHT)
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uniqueField = self.getParameterValue(self.UID)
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if weightField is None:
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weightIndex = -1
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else:
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weightIndex = layer.fieldNameIndex(weightField)
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if uniqueField is None:
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uniqueIndex = -1
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else:
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uniqueIndex = layer.fieldNameIndex(uniqueField)
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fieldList = [QgsField('MEAN_X', QVariant.Double, '', 24, 15),
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QgsField('MEAN_Y', QVariant.Double, '', 24, 15),
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QgsField('UID', QVariant.String, '', 255)]
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
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fieldList, QGis.WKBPoint, layer.crs()
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)
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current = 0
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features = vector.features(layer)
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total = 100.0 / float(len(features))
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means = {}
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for feat in features:
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current += 1
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progress.setPercentage(current * total)
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if uniqueIndex == -1:
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clazz = "Single class"
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else:
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clazz = unicode(feat.attributes()[uniqueIndex]).strip()
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if weightIndex == -1:
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weight = 1.00
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else:
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try:
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weight = float(feat.attributes()[weightIndex])
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except:
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weight = 1.00
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if clazz not in means:
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means[clazz] = (0, 0, 0)
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(cx, cy, totalweight) = means[clazz]
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geom = QgsGeometry(feat.geometry())
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geom = vector.extractPoints(geom)
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for i in geom:
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cx += i.x() * weight
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cy += i.y() * weight
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totalweight += weight
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means[clazz] = (cx, cy, totalweight)
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for (clazz, values) in means.iteritems():
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outFeat = QgsFeature()
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cx = values[0] / values[2]
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cy = values[1] / values[2]
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meanPoint = QgsPoint(cx, cy)
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outFeat.setGeometry(QgsGeometry.fromPoint(meanPoint))
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outFeat.setAttributes([cx, cy, clazz])
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writer.addFeature(outFeat)
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del writer
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