QGIS/python/plugins/processing/algs/qgis/ZonalStatistics.py

133 lines
6.0 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
ZonalStatistics.py
---------------------
Date : September 2016
Copyright : (C) 2016 by Alexander Bruy
Email : alexander dot bruy 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. *
* *
***************************************************************************
"""
__author__ = 'Alexander Bruy'
__date__ = 'September 2016'
__copyright__ = '(C) 2016, Alexander Bruy'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
from collections import OrderedDict
from qgis.PyQt.QtGui import QIcon
from qgis.analysis import QgsZonalStatistics
from qgis.core import (QgsProcessing,
QgsProcessingParameterVectorLayer,
QgsProcessingParameterRasterLayer,
QgsProcessingParameterString,
QgsProcessingParameterBand,
QgsProcessingParameterEnum,
QgsProcessingOutputVectorLayer)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class ZonalStatistics(QgisAlgorithm):
INPUT_RASTER = 'INPUT_RASTER'
RASTER_BAND = 'RASTER_BAND'
INPUT_VECTOR = 'INPUT_VECTOR'
COLUMN_PREFIX = 'COLUMN_PREFIX'
STATISTICS = 'STATS'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'zonalstats.png'))
def group(self):
return self.tr('Raster analysis')
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.STATS = OrderedDict([(self.tr('Count'), QgsZonalStatistics.Count),
(self.tr('Sum'), QgsZonalStatistics.Sum),
(self.tr('Mean'), QgsZonalStatistics.Mean),
(self.tr('Median'), QgsZonalStatistics.Median),
(self.tr('Std. dev.'), QgsZonalStatistics.StDev),
(self.tr('Min'), QgsZonalStatistics.Min),
(self.tr('Max'), QgsZonalStatistics.Max),
(self.tr('Range'), QgsZonalStatistics.Range),
(self.tr('Minority'), QgsZonalStatistics.Minority),
(self.tr('Majority (mode)'), QgsZonalStatistics.Majority),
(self.tr('Variety'), QgsZonalStatistics.Variety),
(self.tr('Variance'), QgsZonalStatistics.Variance),
(self.tr('All'), QgsZonalStatistics.All)])
self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT_RASTER,
self.tr('Raster layer')))
self.addParameter(QgsProcessingParameterBand(self.RASTER_BAND,
self.tr('Raster band'),
1,
self.INPUT_RASTER))
self.addParameter(QgsProcessingParameterVectorLayer(self.INPUT_VECTOR,
self.tr('Vector layer containing zones'),
[QgsProcessing.TypeVectorPolygon]))
self.addParameter(QgsProcessingParameterString(self.COLUMN_PREFIX,
self.tr('Output column prefix'), '_'))
keys = list(self.STATS.keys())
self.addParameter(QgsProcessingParameterEnum(self.STATISTICS,
self.tr('Statistics to calculate'),
keys,
allowMultiple=True, defaultValue=[0, 1, 2]))
self.addOutput(QgsProcessingOutputVectorLayer(self.INPUT_VECTOR,
self.tr('Zonal statistics'),
QgsProcessing.TypeVectorPolygon))
self.bandNumber = None
self.columnPrefix = None
self.selectedStats = None
self.vectorLayer = None
self.rasterLayer = None
def name(self):
return 'zonalstatistics'
def displayName(self):
return self.tr('Zonal statistics')
def prepareAlgorithm(self, parameters, context, feedback):
self.bandNumber = self.parameterAsInt(parameters, self.RASTER_BAND, context)
self.columnPrefix = self.parameterAsString(parameters, self.COLUMN_PREFIX, context)
st = self.parameterAsEnums(parameters, self.STATISTICS, context)
keys = list(self.STATS.keys())
self.selectedStats = 0
for i in st:
self.selectedStats |= self.STATS[keys[i]]
self.vectorLayer = self.parameterAsVectorLayer(parameters, self.INPUT_VECTOR, context)
self.rasterLayer = self.parameterAsRasterLayer(parameters, self.INPUT_RASTER, context)
return True
def processAlgorithm(self, parameters, context, feedback):
zs = QgsZonalStatistics(self.vectorLayer,
self.rasterLayer,
self.columnPrefix,
self.bandNumber,
QgsZonalStatistics.Statistics(self.selectedStats))
zs.calculateStatistics(feedback)
return {self.INPUT_VECTOR: self.vectorLayer}