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			289 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			289 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # -*- coding: utf-8 -*-
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| 
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| """
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| ***************************************************************************
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|     RasterLayerCalculator.py
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|     ---------------------
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|     Date                 : November 2016
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|     Copyright            : (C) 2016 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__ = 'November 2016'
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| __copyright__ = '(C) 2016, Victor Olaya'
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| 
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| import os
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| import math
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| from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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| from processing.algs.gdal.GdalUtils import GdalUtils
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| from qgis.core import (QgsProcessing,
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|                        QgsProcessingException,
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|                        QgsProcessingUtils,
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|                        QgsProcessingParameterCrs,
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|                        QgsProcessingParameterMultipleLayers,
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|                        QgsProcessingParameterNumber,
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|                        QgsProcessingParameterExtent,
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|                        QgsProcessingParameterRasterDestination,
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|                        QgsProcessingParameterRasterLayer,
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|                        QgsProcessingOutputRasterLayer,
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|                        QgsProcessingParameterString,
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|                        QgsCoordinateTransform,
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|                        QgsMapLayer)
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| from qgis.PyQt.QtCore import QObject
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| from qgis.analysis import QgsRasterCalculator, QgsRasterCalculatorEntry
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| 
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| 
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| class RasterCalculator(QgisAlgorithm):
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| 
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|     LAYERS = 'LAYERS'
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|     EXTENT = 'EXTENT'
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|     CELLSIZE = 'CELLSIZE'
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|     EXPRESSION = 'EXPRESSION'
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|     CRS = 'CRS'
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|     OUTPUT = 'OUTPUT'
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| 
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|     def group(self):
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|         return self.tr('Raster analysis')
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| 
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|     def groupId(self):
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|         return 'rasteranalysis'
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| 
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|     def __init__(self):
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|         super().__init__()
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| 
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|     def initAlgorithm(self, config=None):
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|         class ParameterRasterCalculatorExpression(QgsProcessingParameterString):
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| 
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|             def __init__(self, name='', description='', multiLine=False):
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|                 super().__init__(name, description, multiLine=multiLine)
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|                 self.setMetadata({
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|                     'widget_wrapper': 'processing.algs.qgis.ui.RasterCalculatorWidgets.ExpressionWidgetWrapper'
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|                 })
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| 
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|             def type(self):
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|                 return 'raster_calc_expression'
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| 
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|             def clone(self):
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|                 return ParameterRasterCalculatorExpression(self.name(), self.description(), self.multiLine())
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| 
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|         self.addParameter(ParameterRasterCalculatorExpression(self.EXPRESSION, self.tr('Expression'),
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|                                                               multiLine=True))
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|         self.addParameter(QgsProcessingParameterMultipleLayers(self.LAYERS,
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|                                                                self.tr('Reference layer(s) (used for automated extent, cellsize, and CRS)'),
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|                                                                layerType=QgsProcessing.TypeRaster,
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|                                                                optional=True))
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|         self.addParameter(QgsProcessingParameterNumber(self.CELLSIZE,
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|                                                        self.tr('Cell size (use 0 or empty to set it automatically)'),
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|                                                        type=QgsProcessingParameterNumber.Double,
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|                                                        minValue=0.0, defaultValue=0.0, optional=True))
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|         self.addParameter(QgsProcessingParameterExtent(self.EXTENT,
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|                                                        self.tr('Output extent'),
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|                                                        optional=True))
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|         self.addParameter(QgsProcessingParameterCrs(self.CRS, 'Output CRS', optional=True))
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|         self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('Output')))
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| 
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|     def name(self):
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|         return 'rastercalculator'
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| 
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|     def displayName(self):
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|         return self.tr('Raster calculator')
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| 
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|     def processAlgorithm(self, parameters, context, feedback):
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|         expression = self.parameterAsString(parameters, self.EXPRESSION, context)
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|         layers = self.parameterAsLayerList(parameters, self.LAYERS, context)
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| 
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|         layersDict = {}
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|         if layers:
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|             layersDict = {lyr.source(): lyr for lyr in layers}
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| 
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|         crs = self.parameterAsCrs(parameters, self.CRS, context)
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|         if crs is None or not crs.isValid():
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|             if not layers:
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|                 raise QgsProcessingException(self.tr("No reference layer selected nor CRS provided"))
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|             else:
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|                 crs = list(layersDict.values())[0].crs()
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| 
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|         bbox = self.parameterAsExtent(parameters, self.EXTENT, context)
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|         if bbox.isNull() and not layers:
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|             raise QgsProcessingException(self.tr("No reference layer selected nor extent box provided"))
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| 
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|         if not bbox.isNull():
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|             bboxCrs = self.parameterAsExtentCrs(parameters, self.EXTENT, context)
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|             if bboxCrs != crs:
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|                 transform = QgsCoordinateTransform(bboxCrs, crs, context.project())
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|                 bbox = transform.transformBoundingBox(bbox)
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| 
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|         if bbox.isNull() and layers:
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|             bbox = QgsProcessingUtils.combineLayerExtents(layers, crs, context)
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| 
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|         cellsize = self.parameterAsDouble(parameters, self.CELLSIZE, context)
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|         if cellsize == 0 and not layers:
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|             raise QgsProcessingException(self.tr("No reference layer selected nor cellsize value provided"))
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| 
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|         def _cellsize(layer):
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|             ext = layer.extent()
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|             if layer.crs() != crs:
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|                 transform = QgsCoordinateTransform(layer.crs(), crs, context.project())
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|                 ext = transform.transformBoundingBox(ext)
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|             return (ext.xMaximum() - ext.xMinimum()) / layer.width()
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|         if cellsize == 0:
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|             cellsize = min([_cellsize(lyr) for lyr in layersDict.values()])
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| 
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|         # check for layers available in the model
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|         layersDictCopy = layersDict.copy() # need a shallow copy because next calls invalidate iterator
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|         for lyr in layersDictCopy.values():
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|             expression = self.mappedNameToLayer(lyr, expression, layersDict, context)
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| 
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|         # check for layers available in the project
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|         for lyr in QgsProcessingUtils.compatibleRasterLayers(context.project()):
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|             expression = self.mappedNameToLayer(lyr, expression, layersDict, context)
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| 
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|         # create the list of layers to be passed as inputs to RasterCalculaltor
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|         # at this phase expression has been modified to match available layers
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|         # in the current scope
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|         entries = []
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|         for name, lyr in layersDict.items():
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|             for n in range(lyr.bandCount()):
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|                 ref = '{:s}@{:d}'.format(name, n + 1)
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| 
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|                 if ref in expression:
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|                     entry = QgsRasterCalculatorEntry()
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|                     entry.ref = ref
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|                     entry.raster = lyr
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|                     entry.bandNumber = n + 1
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|                     entries.append(entry)
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| 
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|         # Append any missing entry from the current project
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|         for entry in QgsRasterCalculatorEntry.rasterEntries():
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|             if not [e for e in entries if e.ref == entry.ref]:
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|                 entries.append(entry)
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| 
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|         output = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
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| 
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|         width = round((bbox.xMaximum() - bbox.xMinimum()) / cellsize)
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|         height = round((bbox.yMaximum() - bbox.yMinimum()) / cellsize)
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|         driverName = GdalUtils.getFormatShortNameFromFilename(output)
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| 
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|         calc = QgsRasterCalculator(expression,
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|                                    output,
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|                                    driverName,
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|                                    bbox,
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|                                    crs,
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|                                    width,
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|                                    height,
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|                                    entries,
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|                                    context.transformContext())
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| 
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|         res = calc.processCalculation(feedback)
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|         if res == QgsRasterCalculator.ParserError:
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|             raise QgsProcessingException(self.tr("Error parsing formula"))
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| 
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|         return {self.OUTPUT: output}
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| 
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|     def processBeforeAddingToModeler(self, algorithm, model):
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|         values = []
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|         expression = algorithm.params[self.EXPRESSION]
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|         for i in list(model.inputs.values()):
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|             param = i.param
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|             if isinstance(param, QgsProcessingParameterRasterLayer) and "{}@".format(param.name) in expression:
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|                 values.append(ValueFromInput(param.name()))
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| 
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|         if algorithm.name:
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|             dependent = model.getDependentAlgorithms(algorithm.name)
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|         else:
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|             dependent = []
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|         for alg in list(model.algs.values()):
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|             if alg.modeler_name not in dependent:
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|                 for out in alg.algorithm.outputs:
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|                     if (isinstance(out, QgsProcessingOutputRasterLayer) and
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|                             "{}:{}@".format(alg.modeler_name, out.name) in expression):
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|                         values.append(ValueFromOutput(alg.modeler_name, out.name))
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| 
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|         algorithm.params[self.LAYERS] = values
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| 
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|     def mappedNameToLayer(self, lyr, expression, layersDict, context):
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|         '''Try to identify if a real layer is mapped in the expression with a symbolic name.'''
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| 
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|         nameToMap = lyr.source()
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| 
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|         # check if nameToMap is a file
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|         # TODO: what about URI eg for a COG?
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|         if os.path.isfile(nameToMap):
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|             # get only the name without extension and path of the file
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|             nameToMap = os.path.splitext(os.path.basename(nameToMap))[0]
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| 
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|         # check for layers directly added in the expression
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|         if (nameToMap + "@") in expression:
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|             layersDict[nameToMap] = lyr
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| 
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|         # get "algorithm_inputs" scope of the expressionContext related
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|         # with mapped variables
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|         indexOfScope = context.expressionContext().indexOfScope("algorithm_inputs")
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|         if indexOfScope >= 0:
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|             expContextAlgInputsScope = context.expressionContext().scope(indexOfScope)
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| 
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|             # check for the layers that are mapped as input in a model
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|             # to do this check in the latest scope all passed variables
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|             # to look for a variable that is a layer or a string filename
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|             # to a layer
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|             varDescription = None
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|             for varName in expContextAlgInputsScope.variableNames():
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| 
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|                 layerInContext = expContextAlgInputsScope.variable(varName)
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| 
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|                 if not isinstance(layerInContext, str) and not isinstance(layerInContext, QgsMapLayer):
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|                     continue
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| 
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|                 if isinstance(layerInContext, QgsMapLayer) and nameToMap not in layerInContext.source():
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|                     continue
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| 
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|                 varDescription = expContextAlgInputsScope.description(varName)
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| 
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|                 # because there can be variable with None or "" description
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|                 # then skip them
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|                 if not varDescription:
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|                     continue
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| 
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|                 # check if it's description starts with Output as in:
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|                 #    Output 'Output' from algorithm 'calc1'
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|                 # as set in https://github.com/qgis/QGIS/blob/master/src/core/processing/models/qgsprocessingmodelalgorithm.cpp#L516
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|                 # but var in expression is called simply
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|                 #    'Output' from algorithm 'calc1'
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| 
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|                 # get the translation string to use to parse the description
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|                 # HAVE to use the same translated string as in
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|                 # https://github.com/qgis/QGIS/blob/master/src/core/processing/models/qgsprocessingmodelalgorithm.cpp#L516
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|                 translatedDesc = self.tr("Output '%1' from algorithm '%2'")
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|                 elementZero = translatedDesc.split(" ")[0] # For english the string result should be "Output"
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| 
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|                 elements = varDescription.split(" ")
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|                 if len(elements) > 1 and elements[0] == elementZero:
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|                     # remove heading QObject.tr"Output ") string. Note adding a space at the end of elementZero!
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|                     varDescription = varDescription[len(elementZero) + 1:]
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| 
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|                 # check if cleaned varDescription is present in the expression
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|                 # if not skip it
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|                 if (varDescription + "@") not in expression:
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|                     continue
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| 
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|                 # !!!found!!! => substitute in expression
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|                 # and add in the list of layers that will be passed to raster calculator
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|                 nameToMap = varName
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|                 new = "{}@".format(nameToMap)
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|                 old = "{}@".format(varDescription)
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|                 expression = expression.replace(old, new)
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| 
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|                 layersDict[nameToMap] = lyr
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| 
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|         # need return the modified expression because it's not a reference
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|         return expression
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