# -*- coding: utf-8 -*- """ *************************************************************************** Heatmap.py --------------------- Date : November 2016 Copyright : (C) 2016 by Nyall Dawson Email : nyall dot dawson 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__ = 'Nyall Dawson' __date__ = 'November 2016' __copyright__ = '(C) 2016, Nyall Dawson' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import os from qgis.PyQt.QtGui import QIcon from qgis.core import (QgsFeatureRequest, QgsMessageLog, QgsProcessingUtils) from qgis.analysis import QgsKernelDensityEstimation from processing.core.GeoAlgorithm import GeoAlgorithm from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException from processing.core.parameters import ParameterVector from processing.core.parameters import ParameterNumber from processing.core.parameters import ParameterSelection from processing.core.parameters import ParameterTableField from processing.core.outputs import OutputRaster from processing.tools import dataobjects, vector, raster from processing.algs.qgis.ui.HeatmapWidgets import HeatmapPixelSizeWidgetWrapper pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class Heatmap(GeoAlgorithm): INPUT_LAYER = 'INPUT_LAYER' RADIUS = 'RADIUS' RADIUS_FIELD = 'RADIUS_FIELD' WEIGHT_FIELD = 'WEIGHT_FIELD' PIXEL_SIZE = 'PIXEL_SIZE' KERNELS = ['Quartic', 'Triangular', 'Uniform', 'Triweight', 'Epanechnikov' ] KERNEL = 'KERNEL' DECAY = 'DECAY' OUTPUT_VALUES = ['Raw', 'Scaled' ] OUTPUT_VALUE = 'OUTPUT_VALUE' OUTPUT_LAYER = 'OUTPUT_LAYER' def icon(self): return QIcon(os.path.join(pluginPath, 'images', 'heatmap.png')) def tags(self): return self.tr('heatmap,kde,hotspot').split(',') def group(self): return self.tr('Interpolation') def name(self): return 'heatmapkerneldensityestimation' def displayName(self): return self.tr('Heatmap (Kernel Density Estimation)') def defineCharacteristics(self): self.addParameter(ParameterVector(self.INPUT_LAYER, self.tr('Point layer'), [dataobjects.TYPE_VECTOR_POINT])) self.addParameter(ParameterNumber(self.RADIUS, self.tr('Radius (layer units)'), 0.0, 9999999999, 100.0)) radius_field_param = ParameterTableField(self.RADIUS_FIELD, self.tr('Radius from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER) radius_field_param.isAdvanced = True self.addParameter(radius_field_param) class ParameterHeatmapPixelSize(ParameterNumber): def __init__(self, name='', description='', parent_layer=None, radius_param=None, radius_field_param=None, minValue=None, maxValue=None, default=None, optional=False, metadata={}): ParameterNumber.__init__(self, name, description, minValue, maxValue, default, optional, metadata) self.parent_layer = parent_layer self.radius_param = radius_param self.radius_field_param = radius_field_param self.addParameter(ParameterHeatmapPixelSize(self.PIXEL_SIZE, self.tr('Output raster size'), parent_layer=self.INPUT_LAYER, radius_param=self.RADIUS, radius_field_param=self.RADIUS_FIELD, minValue=0.0, maxValue=9999999999, default=0.1, metadata={'widget_wrapper': HeatmapPixelSizeWidgetWrapper})) weight_field_param = ParameterTableField(self.WEIGHT_FIELD, self.tr('Weight from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER) weight_field_param.isAdvanced = True self.addParameter(weight_field_param) kernel_shape_param = ParameterSelection(self.KERNEL, self.tr('Kernel shape'), self.KERNELS) kernel_shape_param.isAdvanced = True self.addParameter(kernel_shape_param) decay_ratio = ParameterNumber(self.DECAY, self.tr('Decay ratio (Triangular kernels only)'), -100.0, 100.0, 0.0) decay_ratio.isAdvanced = True self.addParameter(decay_ratio) output_scaling = ParameterSelection(self.OUTPUT_VALUE, self.tr('Output value scaling'), self.OUTPUT_VALUES) output_scaling.isAdvanced = True self.addParameter(output_scaling) self.addOutput(OutputRaster(self.OUTPUT_LAYER, self.tr('Heatmap'))) def processAlgorithm(self, context, feedback): layer = dataobjects.getLayerFromString( self.getParameterValue(self.INPUT_LAYER)) radius = self.getParameterValue(self.RADIUS) kernel_shape = self.getParameterValue(self.KERNEL) pixel_size = self.getParameterValue(self.PIXEL_SIZE) decay = self.getParameterValue(self.DECAY) output_values = self.getParameterValue(self.OUTPUT_VALUE) output = self.getOutputValue(self.OUTPUT_LAYER) output_format = raster.formatShortNameFromFileName(output) weight_field = self.getParameterValue(self.WEIGHT_FIELD) radius_field = self.getParameterValue(self.RADIUS_FIELD) attrs = [] kde_params = QgsKernelDensityEstimation.Parameters() kde_params.vectorLayer = layer kde_params.radius = radius kde_params.pixelSize = pixel_size # radius field if radius_field: kde_params.radiusField = radius_field attrs.append(layer.fields().lookupField(radius_field)) # weight field if weight_field: kde_params.weightField = weight_field attrs.append(layer.fields().lookupField(weight_field)) kde_params.shape = kernel_shape kde_params.decayRatio = decay kde_params.outputValues = output_values kde = QgsKernelDensityEstimation(kde_params, output, output_format) if kde.prepare() != QgsKernelDensityEstimation.Success: raise GeoAlgorithmExecutionException( self.tr('Could not create destination layer')) request = QgsFeatureRequest() request.setSubsetOfAttributes(attrs) features = QgsProcessingUtils.getFeatures(layer, context, request) total = 100.0 / QgsProcessingUtils.featureCount(layer, context) for current, f in enumerate(features): if kde.addFeature(f) != QgsKernelDensityEstimation.Success: QgsMessageLog.logMessage(self.tr('Error adding feature with ID {} to heatmap').format(f.id()), self.tr('Processing'), QgsMessageLog.CRITICAL) feedback.setProgress(int(current * total)) if kde.finalise() != QgsKernelDensityEstimation.Success: raise GeoAlgorithmExecutionException( self.tr('Could not save destination layer'))