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142 lines
5.2 KiB
Python
142 lines
5.2 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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RandomSelectionWithinSubsets.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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from builtins import range
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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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import os
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import random
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from qgis.PyQt.QtGui import QIcon
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from qgis.core import QgsFeature, QgsFeatureSink, QgsProcessingUtils
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterSelection
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from processing.core.parameters import ParameterVector
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from processing.core.parameters import ParameterNumber
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from processing.core.parameters import ParameterTableField
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from processing.core.outputs import OutputVector
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pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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class RandomSelectionWithinSubsets(QgisAlgorithm):
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INPUT = 'INPUT'
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METHOD = 'METHOD'
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NUMBER = 'NUMBER'
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FIELD = 'FIELD'
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OUTPUT = 'OUTPUT'
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def icon(self):
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return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'sub_selection.png'))
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def group(self):
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return self.tr('Vector selection tools')
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def __init__(self):
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super().__init__()
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self.methods = [self.tr('Number of selected features'),
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self.tr('Percentage of selected features')]
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self.addParameter(ParameterVector(self.INPUT,
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self.tr('Input layer')))
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self.addParameter(ParameterTableField(self.FIELD,
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self.tr('ID Field'), self.INPUT))
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self.addParameter(ParameterSelection(self.METHOD,
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self.tr('Method'), self.methods, 0))
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self.addParameter(ParameterNumber(self.NUMBER,
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self.tr('Number/percentage of selected features'), 1, None, 10))
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self.addOutput(OutputVector(self.OUTPUT, self.tr('Selection stratified'), True))
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def name(self):
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return 'randomselectionwithinsubsets'
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def displayName(self):
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return self.tr('Random selection within subsets')
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def processAlgorithm(self, parameters, context, feedback):
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filename = self.getParameterValue(self.INPUT)
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layer = QgsProcessingUtils.mapLayerFromString(filename, context)
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field = self.getParameterValue(self.FIELD)
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method = self.getParameterValue(self.METHOD)
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layer.removeSelection()
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index = layer.fields().lookupField(field)
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unique = QgsProcessingUtils.uniqueValues(layer, index, context)
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featureCount = layer.featureCount()
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value = int(self.getParameterValue(self.NUMBER))
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if method == 0:
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if value > featureCount:
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raise GeoAlgorithmExecutionException(
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self.tr('Selected number is greater that feature count. '
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'Choose lesser value and try again.'))
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else:
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if value > 100:
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raise GeoAlgorithmExecutionException(
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self.tr("Percentage can't be greater than 100. Set a "
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"different value and try again."))
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value = value / 100.0
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selran = []
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inFeat = QgsFeature()
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current = 0
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total = 100.0 / (featureCount * len(unique)) if featureCount else 1
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if not len(unique) == featureCount:
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for i in unique:
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features = QgsProcessingUtils.getFeatures(layer, context)
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FIDs = []
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for inFeat in features:
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attrs = inFeat.attributes()
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if attrs[index] == i:
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FIDs.append(inFeat.id())
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current += 1
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feedback.setProgress(int(current * total))
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if method == 1:
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selValue = int(round(value * len(FIDs), 0))
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else:
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selValue = value
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if selValue >= len(FIDs):
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selFeat = FIDs
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else:
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selFeat = random.sample(FIDs, selValue)
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selran.extend(selFeat)
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layer.selectByIds(selran)
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else:
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layer.selectByIds(list(range(featureCount))) # FIXME: implies continuous feature ids
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self.setOutputValue(self.OUTPUT, filename)
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