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			82 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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    Centroids.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 archive323
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__revision__ = '$Format:%H$'
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from qgis.core import QGis, QgsGeometry, QgsFeature
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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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 Centroids(GeoAlgorithm):
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    INPUT_LAYER = 'INPUT_LAYER'
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    OUTPUT_LAYER = 'OUTPUT_LAYER'
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    def defineCharacteristics(self):
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        self.name, self.i18n_name = self.trAlgorithm('Polygon centroids')
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        self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
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        self.addParameter(ParameterVector(self.INPUT_LAYER,
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                                          self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
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        self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Centroids')))
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    def processAlgorithm(self, progress):
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        layer = dataobjects.getObjectFromUri(
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            self.getParameterValue(self.INPUT_LAYER))
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        writer = self.getOutputFromName(
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            self.OUTPUT_LAYER).getVectorWriter(
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                layer.pendingFields().toList(),
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                QGis.WKBPoint,
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                layer.crs())
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        outFeat = QgsFeature()
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        features = vector.features(layer)
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        total = 100.0 / float(len(features))
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        current = 0
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        for inFeat in features:
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            inGeom = inFeat.geometry()
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            attrs = inFeat.attributes()
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            outGeom = QgsGeometry(inGeom.centroid())
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            if outGeom is None:
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                raise GeoAlgorithmExecutionException(
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                    self.tr('Error calculating centroid'))
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            outFeat.setGeometry(outGeom)
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            outFeat.setAttributes(attrs)
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            writer.addFeature(outFeat)
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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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