mirror of
https://github.com/qgis/QGIS.git
synced 2025-11-04 00:04:25 -05:00
f247a7cda3
Remove processing vector.uniqueValues/vector.getUniqueValues and port usage to c++ method Should be much faster than the python method, as the c++ method takes advantage of handing off the unique values calculation to the provider source whenever possible
130 lines
5.1 KiB
Python
130 lines
5.1 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
RandomSelectionWithinSubsets.py
|
|
---------------------
|
|
Date : August 2012
|
|
Copyright : (C) 2012 by Victor Olaya
|
|
Email : volayaf at gmail dot com
|
|
***************************************************************************
|
|
* *
|
|
* This program is free software; you can redistribute it and/or modify *
|
|
* it under the terms of the GNU General Public License as published by *
|
|
* the Free Software Foundation; either version 2 of the License, or *
|
|
* (at your option) any later version. *
|
|
* *
|
|
***************************************************************************
|
|
"""
|
|
from builtins import range
|
|
|
|
__author__ = 'Victor Olaya'
|
|
__date__ = 'August 2012'
|
|
__copyright__ = '(C) 2012, Victor Olaya'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
import random
|
|
|
|
from qgis.core import (QgsApplication,
|
|
QgsProcessingUtils)
|
|
from collections import defaultdict
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
|
|
from processing.core.parameters import ParameterSelection
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.parameters import ParameterNumber
|
|
from processing.core.parameters import ParameterTableField
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import dataobjects, vector
|
|
|
|
|
|
class RandomExtractWithinSubsets(GeoAlgorithm):
|
|
|
|
INPUT = 'INPUT'
|
|
METHOD = 'METHOD'
|
|
NUMBER = 'NUMBER'
|
|
FIELD = 'FIELD'
|
|
OUTPUT = 'OUTPUT'
|
|
|
|
def icon(self):
|
|
return QgsApplication.getThemeIcon("/providerQgis.svg")
|
|
|
|
def svgIconPath(self):
|
|
return QgsApplication.iconPath("providerQgis.svg")
|
|
|
|
def group(self):
|
|
return self.tr('Vector selection tools')
|
|
|
|
def name(self):
|
|
return 'randomextractwithinsubsets'
|
|
|
|
def displayName(self):
|
|
return self.tr('Random extract within subsets')
|
|
|
|
def defineCharacteristics(self):
|
|
self.methods = [self.tr('Number of selected features'),
|
|
self.tr('Percentage of selected features')]
|
|
|
|
self.addParameter(ParameterVector(self.INPUT,
|
|
self.tr('Input layer')))
|
|
self.addParameter(ParameterTableField(self.FIELD,
|
|
self.tr('ID field'), self.INPUT))
|
|
self.addParameter(ParameterSelection(self.METHOD,
|
|
self.tr('Method'), self.methods, 0))
|
|
self.addParameter(ParameterNumber(self.NUMBER,
|
|
self.tr('Number/percentage of selected features'), 1, None, 10))
|
|
|
|
self.addOutput(OutputVector(self.OUTPUT, self.tr('Extracted (random stratified)')))
|
|
|
|
def processAlgorithm(self, context, feedback):
|
|
filename = self.getParameterValue(self.INPUT)
|
|
|
|
layer = dataobjects.getLayerFromString(filename)
|
|
field = self.getParameterValue(self.FIELD)
|
|
method = self.getParameterValue(self.METHOD)
|
|
|
|
index = layer.fields().lookupField(field)
|
|
|
|
features = QgsProcessingUtils.getFeatures(layer, context)
|
|
featureCount = QgsProcessingUtils.featureCount(layer, context)
|
|
unique = QgsProcessingUtils.uniqueValues(layer, index, context)
|
|
value = int(self.getParameterValue(self.NUMBER))
|
|
if method == 0:
|
|
if value > featureCount:
|
|
raise GeoAlgorithmExecutionException(
|
|
self.tr('Selected number is greater that feature count. '
|
|
'Choose lesser value and try again.'))
|
|
else:
|
|
if value > 100:
|
|
raise GeoAlgorithmExecutionException(
|
|
self.tr("Percentage can't be greater than 100. Set "
|
|
"correct value and try again."))
|
|
value = value / 100.0
|
|
|
|
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
|
|
layer.fields().toList(), layer.wkbType(), layer.crs())
|
|
|
|
selran = []
|
|
total = 100.0 / (featureCount * len(unique))
|
|
features = QgsProcessingUtils.getFeatures(layer, context)
|
|
|
|
classes = defaultdict(list)
|
|
for i, feature in enumerate(features):
|
|
attrs = feature.attributes()
|
|
classes[attrs[index]].append(feature)
|
|
feedback.setProgress(int(i * total))
|
|
|
|
for subset in classes.values():
|
|
selValue = value if method != 1 else int(round(value * len(subset), 0))
|
|
selran.extend(random.sample(subset, selValue))
|
|
|
|
features = QgsProcessingUtils.getFeatures(layer, context)
|
|
total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
|
|
for (i, feat) in enumerate(selran):
|
|
writer.addFeature(feat)
|
|
feedback.setProgress(int(i * total))
|
|
del writer
|