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			229 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			229 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # -*- coding: utf-8 -*-
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| 
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| """
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| ***************************************************************************
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|     Heatmap.py
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|     ---------------------
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|     Date                 : November 2016
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|     Copyright            : (C) 2016 by Nyall Dawson
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|     Email                : nyall dot dawson 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__ = 'Nyall Dawson'
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| __date__ = 'November 2016'
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| __copyright__ = '(C) 2016, Nyall Dawson'
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| 
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| import os
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| from collections import OrderedDict
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| 
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| from qgis.PyQt.QtGui import QIcon
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| 
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| from qgis.core import (QgsApplication,
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|                        QgsFeatureRequest,
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|                        QgsRasterFileWriter,
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|                        QgsProcessing,
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|                        QgsProcessingException,
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|                        QgsProcessingParameterFeatureSource,
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|                        QgsProcessingParameterNumber,
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|                        QgsProcessingParameterDistance,
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|                        QgsProcessingParameterField,
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|                        QgsProcessingParameterEnum,
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|                        QgsProcessingParameterDefinition,
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|                        QgsProcessingParameterRasterDestination)
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| 
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| from qgis.analysis import QgsKernelDensityEstimation
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| 
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| from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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| 
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| pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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| 
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| 
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| class Heatmap(QgisAlgorithm):
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|     INPUT = 'INPUT'
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|     RADIUS = 'RADIUS'
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|     RADIUS_FIELD = 'RADIUS_FIELD'
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|     WEIGHT_FIELD = 'WEIGHT_FIELD'
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|     PIXEL_SIZE = 'PIXEL_SIZE'
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|     KERNEL = 'KERNEL'
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|     DECAY = 'DECAY'
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|     OUTPUT_VALUE = 'OUTPUT_VALUE'
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|     OUTPUT = 'OUTPUT'
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| 
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|     def icon(self):
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|         return QgsApplication.getThemeIcon("/heatmap.svg")
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| 
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|     def tags(self):
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|         return self.tr('heatmap,kde,hotspot').split(',')
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| 
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|     def group(self):
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|         return self.tr('Interpolation')
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| 
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|     def groupId(self):
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|         return 'interpolation'
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| 
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|     def name(self):
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|         return 'heatmapkerneldensityestimation'
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| 
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|     def displayName(self):
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|         return self.tr('Heatmap (Kernel Density Estimation)')
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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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|         self.KERNELS = OrderedDict([(self.tr('Quartic'), QgsKernelDensityEstimation.KernelQuartic),
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|                                     (self.tr('Triangular'), QgsKernelDensityEstimation.KernelTriangular),
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|                                     (self.tr('Uniform'), QgsKernelDensityEstimation.KernelUniform),
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|                                     (self.tr('Triweight'), QgsKernelDensityEstimation.KernelTriweight),
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|                                     (self.tr('Epanechnikov'), QgsKernelDensityEstimation.KernelEpanechnikov)])
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| 
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|         self.OUTPUT_VALUES = OrderedDict([(self.tr('Raw'), QgsKernelDensityEstimation.OutputRaw),
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|                                           (self.tr('Scaled'), QgsKernelDensityEstimation.OutputScaled)])
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| 
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|         self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
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|                                                               self.tr('Point layer'),
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|                                                               [QgsProcessing.TypeVectorPoint]))
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| 
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|         self.addParameter(QgsProcessingParameterDistance(self.RADIUS,
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|                                                          self.tr('Radius'),
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|                                                          100.0, self.INPUT, False, 0.0))
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| 
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|         radius_field_param = QgsProcessingParameterField(self.RADIUS_FIELD,
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|                                                          self.tr('Radius from field'),
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|                                                          None,
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|                                                          self.INPUT,
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|                                                          QgsProcessingParameterField.Numeric,
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|                                                          optional=True
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|                                                          )
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|         radius_field_param.setFlags(radius_field_param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
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|         self.addParameter(radius_field_param)
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| 
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|         class ParameterHeatmapPixelSize(QgsProcessingParameterNumber):
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| 
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|             def __init__(self, name='', description='', parent_layer=None, radius_param=None, radius_field_param=None, minValue=None,
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|                          default=None, optional=False):
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|                 QgsProcessingParameterNumber.__init__(self, name, description, QgsProcessingParameterNumber.Double, default, optional, minValue)
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|                 self.parent_layer = parent_layer
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|                 self.radius_param = radius_param
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|                 self.radius_field_param = radius_field_param
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| 
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|             def clone(self):
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|                 copy = ParameterHeatmapPixelSize(self.name(), self.description(), self.parent_layer, self.radius_param, self.radius_field_param, self.minimum(), self.maximum(), self.defaultValue((), self.flags() & QgsProcessingParameterDefinition.FlagOptional))
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|                 return copy
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| 
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|         pixel_size_param = ParameterHeatmapPixelSize(self.PIXEL_SIZE,
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|                                                      self.tr('Output raster size'),
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|                                                      parent_layer=self.INPUT,
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|                                                      radius_param=self.RADIUS,
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|                                                      radius_field_param=self.RADIUS_FIELD,
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|                                                      minValue=0.0,
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|                                                      default=0.1)
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|         pixel_size_param.setMetadata({
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|             'widget_wrapper': {
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|                 'class': 'processing.algs.qgis.ui.HeatmapWidgets.HeatmapPixelSizeWidgetWrapper'}})
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|         self.addParameter(pixel_size_param)
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| 
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|         weight_field_param = QgsProcessingParameterField(self.WEIGHT_FIELD,
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|                                                          self.tr('Weight from field'),
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|                                                          None,
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|                                                          self.INPUT,
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|                                                          QgsProcessingParameterField.Numeric,
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|                                                          optional=True
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|                                                          )
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|         weight_field_param.setFlags(weight_field_param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
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|         self.addParameter(weight_field_param)
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| 
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|         keys = list(self.KERNELS.keys())
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|         kernel_shape_param = QgsProcessingParameterEnum(self.KERNEL,
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|                                                         self.tr('Kernel shape'),
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|                                                         keys,
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|                                                         allowMultiple=False,
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|                                                         defaultValue=0)
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|         kernel_shape_param.setFlags(kernel_shape_param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
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|         self.addParameter(kernel_shape_param)
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| 
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|         decay_ratio = QgsProcessingParameterNumber(self.DECAY,
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|                                                    self.tr('Decay ratio (Triangular kernels only)'),
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|                                                    QgsProcessingParameterNumber.Double,
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|                                                    0.0, True, -100.0, 100.0)
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|         decay_ratio.setFlags(decay_ratio.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
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|         self.addParameter(decay_ratio)
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| 
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|         keys = list(self.OUTPUT_VALUES.keys())
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|         output_scaling = QgsProcessingParameterEnum(self.OUTPUT_VALUE,
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|                                                     self.tr('Output value scaling'),
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|                                                     keys,
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|                                                     allowMultiple=False,
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|                                                     defaultValue=0)
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|         output_scaling.setFlags(output_scaling.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
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|         self.addParameter(output_scaling)
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| 
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|         self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('Heatmap')))
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| 
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|     def processAlgorithm(self, parameters, context, feedback):
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|         source = self.parameterAsSource(parameters, self.INPUT, context)
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|         if source is None:
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|             raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
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| 
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|         radius = self.parameterAsDouble(parameters, self.RADIUS, context)
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|         kernel_shape = self.parameterAsEnum(parameters, self.KERNEL, context)
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|         pixel_size = self.parameterAsDouble(parameters, self.PIXEL_SIZE, context)
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|         decay = self.parameterAsDouble(parameters, self.DECAY, context)
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|         output_values = self.parameterAsEnum(parameters, self.OUTPUT_VALUE, context)
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|         outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
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|         output_format = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
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|         weight_field = self.parameterAsString(parameters, self.WEIGHT_FIELD, context)
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|         radius_field = self.parameterAsString(parameters, self.RADIUS_FIELD, context)
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| 
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|         attrs = []
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| 
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|         kde_params = QgsKernelDensityEstimation.Parameters()
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|         kde_params.source = source
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|         kde_params.radius = radius
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|         kde_params.pixelSize = pixel_size
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|         # radius field
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|         if radius_field:
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|             kde_params.radiusField = radius_field
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|             attrs.append(source.fields().lookupField(radius_field))
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|         # weight field
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|         if weight_field:
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|             kde_params.weightField = weight_field
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|             attrs.append(source.fields().lookupField(weight_field))
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| 
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|         kde_params.shape = kernel_shape
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|         kde_params.decayRatio = decay
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|         kde_params.outputValues = output_values
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| 
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|         kde = QgsKernelDensityEstimation(kde_params, outputFile, output_format)
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| 
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|         if kde.prepare() != QgsKernelDensityEstimation.Success:
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|             raise QgsProcessingException(
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|                 self.tr('Could not create destination layer'))
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| 
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|         request = QgsFeatureRequest()
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|         request.setSubsetOfAttributes(attrs)
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|         features = source.getFeatures(request)
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|         total = 100.0 / source.featureCount() if source.featureCount() else 0
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|         for current, f in enumerate(features):
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|             if feedback.isCanceled():
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|                 break
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| 
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|             if kde.addFeature(f) != QgsKernelDensityEstimation.Success:
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|                 feedback.reportError(self.tr('Error adding feature with ID {} to heatmap').format(f.id()))
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| 
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|             feedback.setProgress(int(current * total))
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| 
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|         if kde.finalise() != QgsKernelDensityEstimation.Success:
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|             raise QgsProcessingException(
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|                 self.tr('Could not save destination layer'))
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| 
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|         return {self.OUTPUT: outputFile}
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