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	For BasicStatisticssNumbers and StatisticsByCategories algorithms. Adds extra stats (minority, majority, 1st/3rd quartile and IQR) while avoiding custom statistics calculation code.
		
			
				
	
	
		
			94 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			94 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # -*- coding: utf-8 -*-
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| 
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| """
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| ***************************************************************************
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|     StatisticsByCategories.py
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|     ---------------------
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|     Date                 : September 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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| 
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| __author__ = 'Victor Olaya'
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| __date__ = 'September 2012'
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| __copyright__ = '(C) 2012, Victor Olaya'
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| 
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| # This will get replaced with a git SHA1 when you do a git archive
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| 
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| __revision__ = '$Format:%H$'
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| 
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| from qgis.core import QgsStatisticalSummary
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| from processing.core.outputs import OutputTable
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| from processing.core.GeoAlgorithm import GeoAlgorithm
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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.parameters import ParameterTableField
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| 
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| 
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| class StatisticsByCategories(GeoAlgorithm):
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| 
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|     INPUT_LAYER = 'INPUT_LAYER'
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|     VALUES_FIELD_NAME = 'VALUES_FIELD_NAME'
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|     CATEGORIES_FIELD_NAME = 'CATEGORIES_FIELD_NAME'
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|     OUTPUT = 'OUTPUT'
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| 
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|     def defineCharacteristics(self):
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|         self.name, self.i18n_name = self.trAlgorithm('Statistics by categories')
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|         self.group, self.i18n_group = self.trAlgorithm('Vector table tools')
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| 
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|         self.addParameter(ParameterVector(self.INPUT_LAYER,
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|                                           self.tr('Input vector layer'), [ParameterVector.VECTOR_TYPE_ANY], False))
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|         self.addParameter(ParameterTableField(self.VALUES_FIELD_NAME,
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|                                               self.tr('Field to calculate statistics on'),
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|                                               self.INPUT_LAYER, ParameterTableField.DATA_TYPE_NUMBER))
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|         self.addParameter(ParameterTableField(self.CATEGORIES_FIELD_NAME,
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|                                               self.tr('Field with categories'),
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|                                               self.INPUT_LAYER, ParameterTableField.DATA_TYPE_ANY))
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| 
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|         self.addOutput(OutputTable(self.OUTPUT, self.tr('Statistics by category')))
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| 
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|     def processAlgorithm(self, progress):
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|         layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))
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|         valuesFieldName = self.getParameterValue(self.VALUES_FIELD_NAME)
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|         categoriesFieldName = self.getParameterValue(self.CATEGORIES_FIELD_NAME)
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| 
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|         output = self.getOutputFromName(self.OUTPUT)
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|         valuesField = layer.fieldNameIndex(valuesFieldName)
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|         categoriesField = layer.fieldNameIndex(categoriesFieldName)
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| 
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|         features = vector.features(layer)
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|         nFeats = len(features)
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|         values = {}
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|         nFeat = 0
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|         for feat in features:
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|             nFeat += 1
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|             progress.setPercentage(int(100 * nFeats / nFeat))
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|             attrs = feat.attributes()
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|             try:
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|                 value = float(attrs[valuesField])
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|                 cat = unicode(attrs[categoriesField])
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|                 if cat not in values:
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|                     values[cat] = []
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|                 values[cat].append(value)
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|             except:
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|                 pass
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| 
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|         fields = ['category', 'min', 'max', 'mean', 'stddev', 'sum', 'count']
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|         writer = output.getTableWriter(fields)
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|         stat = QgsStatisticalSummary(QgsStatisticalSummary.Min | QgsStatisticalSummary.Max |
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|                                      QgsStatisticalSummary.Mean | QgsStatisticalSummary.StDevSample |
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|                                      QgsStatisticalSummary.Sum | QgsStatisticalSummary.Count)
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| 
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|         for (cat, v) in values.items():
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|             stat.calculate(v)
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|             record = [cat, stat.min(), stat.max(), stat.mean(), stat.sampleStDev(), stat.sum(), stat.count()]
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|             writer.addRecord(record)
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