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nyalldawsonnyalldawson
committedDec 6, 2016
[FEATURE][processing] Port heatmap plugin to processing algorithm
·
ltr-3_40final-3_0_0
1 parent f212746 commit 83c38b0

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‎python/plugins/processing/algs/qgis/Heatmap.py

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# -*- coding: utf-8 -*-
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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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__author__ = 'Nyall Dawson'
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__date__ = 'November 2016'
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__copyright__ = '(C) 2016, Nyall Dawson'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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import os
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from qgis.PyQt.QtGui import QIcon
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from qgis.core import QgsFeatureRequest
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from qgis.analysis import QgsKernelDensityEstimation
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterVector
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from processing.core.parameters import ParameterNumber
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from processing.core.parameters import ParameterExtent
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from processing.core.parameters import ParameterSelection
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from processing.core.parameters import ParameterTableField
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from processing.core.outputs import OutputRaster
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from processing.tools import dataobjects, vector, raster
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pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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class Heatmap(GeoAlgorithm):
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INPUT_LAYER = 'INPUT_LAYER'
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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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KERNELS = ['Quartic',
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'Triangular',
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'Uniform',
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'Triweight',
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'Epanechnikov'
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]
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KERNEL = 'KERNEL'
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DECAY = 'DECAY'
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OUTPUT_VALUES = ['Raw',
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'Scaled'
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]
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OUTPUT_VALUE = 'OUTPUT_VALUE'
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OUTPUT_LAYER = 'OUTPUT_LAYER'
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def getIcon(self):
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return QIcon(os.path.join(pluginPath, 'images', 'heatmap.png'))
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Heatmap (Kernel Density Estimation)')
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self.group, self.i18n_group = self.trAlgorithm('Interpolation')
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self.tags = self.tr('heatmap,kde,hotspot')
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self.addParameter(ParameterVector(self.INPUT_LAYER,
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self.tr('Point layer'), [dataobjects.TYPE_VECTOR_POINT]))
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self.addParameter(ParameterNumber(self.RADIUS,
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self.tr('Radius (layer units)'),
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0.0, 9999999999, 100.0))
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self.addParameter(ParameterNumber(self.PIXEL_SIZE,
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self.tr('Output pixel size (layer units)'),
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0.0, 9999999999, 0.1))
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self.addParameter(ParameterTableField(self.RADIUS_FIELD,
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self.tr('Radius from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER))
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self.addParameter(ParameterTableField(self.WEIGHT_FIELD,
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self.tr('Weight from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER))
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self.addParameter(ParameterSelection(self.KERNEL,
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self.tr('Kernel shape'), self.KERNELS))
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self.addParameter(ParameterNumber(self.DECAY,
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self.tr('Decay ratio (Triangular kernels only)'),
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-100.0, 100.0, 0.0))
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self.addParameter(ParameterSelection(self.OUTPUT_VALUE,
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self.tr('Output value scaling'), self.OUTPUT_VALUES))
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self.addOutput(OutputRaster(self.OUTPUT_LAYER,
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self.tr('Heatmap')))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(
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self.getParameterValue(self.INPUT_LAYER))
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radius = self.getParameterValue(self.RADIUS)
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kernel_shape = self.getParameterValue(self.KERNEL)
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pixel_size = self.getParameterValue(self.PIXEL_SIZE)
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decay = self.getParameterValue(self.DECAY)
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output_values = self.getParameterValue(self.OUTPUT_VALUE)
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output = self.getOutputValue(self.OUTPUT_LAYER)
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output_format = raster.formatShortNameFromFileName(output)
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weight_field = self.getParameterValue(self.WEIGHT_FIELD)
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radius_field = self.getParameterValue(self.RADIUS_FIELD)
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attrs = []
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kde_params = QgsKernelDensityEstimation.Parameters()
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kde_params.vectorLayer = layer
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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(layer.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(layer.fields().lookupField(weight_field))
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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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kde = QgsKernelDensityEstimation(kde_params, output, output_format)
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if kde.prepare() != QgsKernelDensityEstimation.Success:
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raise GeoAlgorithmExecutionException(
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self.tr('Could not create destination layer'))
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request = QgsFeatureRequest()
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request.setSubsetOfAttributes(attrs)
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features = vector.features(layer, request)
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total = 100.0 / len(features)
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for current, f in enumerate(features):
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if kde.addFeature(f) != QgsKernelDensityEstimation.Success:
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raise GeoAlgorithmExecutionException(
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self.tr('Error adding feature to heatmap'))
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progress.setPercentage(int(current * total))
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if kde.finalise() != QgsKernelDensityEstimation.Success:
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raise GeoAlgorithmExecutionException(
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self.tr('Could not save destination layer'))

‎python/plugins/processing/algs/qgis/IdwInterpolationZValue.py

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)
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterVector
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from processing.core.parameters import ParameterSelection
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from processing.core.parameters import ParameterNumber

‎python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

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from .CreateAttributeIndex import CreateAttributeIndex
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from .DropGeometry import DropGeometry
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from .BasicStatistics import BasicStatisticsForField
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from .Heatmap import Heatmap
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pluginPath = os.path.normpath(os.path.join(
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os.path.split(os.path.dirname(__file__))[0], os.pardir))
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RemoveNullGeometry(), ExtractByExpression(), ExtendLines(),
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ExtractSpecificNodes(), GeometryByExpression(), SnapGeometriesToLayer(),
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PoleOfInaccessibility(), CreateAttributeIndex(), DropGeometry(),
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BasicStatisticsForField(), RasterCalculator()
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BasicStatisticsForField(), RasterCalculator(), Heatmap()
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]
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if hasMatplotlib:

‎python/plugins/processing/images/heatmap.png

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