[FEATURE][processing] Port heatmap plugin to processing algorithm

qgis · Dec 6, 2016 · 83c38b0 · 83c38b0
1 parent f212746
commit 83c38b0
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diff --git a/python/plugins/processing/algs/qgis/Heatmap.py b/python/plugins/processing/algs/qgis/Heatmap.py
@@ -0,0 +1,152 @@
+# -*- 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
+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 ParameterExtent
+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
+
+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 getIcon(self):
+        return QIcon(os.path.join(pluginPath, 'images', 'heatmap.png'))
+
+    def defineCharacteristics(self):
+        self.name, self.i18n_name = self.trAlgorithm('Heatmap (Kernel Density Estimation)')
+        self.group, self.i18n_group = self.trAlgorithm('Interpolation')
+        self.tags = self.tr('heatmap,kde,hotspot')
+
+        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))
+        self.addParameter(ParameterNumber(self.PIXEL_SIZE,
+                                          self.tr('Output pixel size (layer units)'),
+                                          0.0, 9999999999, 0.1))
+        self.addParameter(ParameterTableField(self.RADIUS_FIELD,
+                                              self.tr('Radius from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER))
+        self.addParameter(ParameterTableField(self.WEIGHT_FIELD,
+                                              self.tr('Weight from field'), self.INPUT_LAYER, optional=True, datatype=ParameterTableField.DATA_TYPE_NUMBER))
+        self.addParameter(ParameterSelection(self.KERNEL,
+                                             self.tr('Kernel shape'), self.KERNELS))
+        self.addParameter(ParameterNumber(self.DECAY,
+                                          self.tr('Decay ratio (Triangular kernels only)'),
+                                          -100.0, 100.0, 0.0))
+        self.addParameter(ParameterSelection(self.OUTPUT_VALUE,
+                                             self.tr('Output value scaling'), self.OUTPUT_VALUES))
+        self.addOutput(OutputRaster(self.OUTPUT_LAYER,
+                                    self.tr('Heatmap')))
+
+    def processAlgorithm(self, progress):
+        layer = dataobjects.getObjectFromUri(
+            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 = vector.features(layer, request)
+        total = 100.0 / len(features)
+        for current, f in enumerate(features):
+            if kde.addFeature(f) != QgsKernelDensityEstimation.Success:
+                raise GeoAlgorithmExecutionException(
+                    self.tr('Error adding feature to heatmap'))
+
+            progress.setPercentage(int(current * total))
+
+        if kde.finalise() != QgsKernelDensityEstimation.Success:
+            raise GeoAlgorithmExecutionException(
+                self.tr('Could not save destination layer'))
diff --git a/python/plugins/processing/algs/qgis/IdwInterpolationZValue.py b/python/plugins/processing/algs/qgis/IdwInterpolationZValue.py
@@ -36,6 +36,7 @@
                            )
 
 from processing.core.GeoAlgorithm import GeoAlgorithm
+from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
 from processing.core.parameters import ParameterVector
 from processing.core.parameters import ParameterSelection
 from processing.core.parameters import ParameterNumber

diff --git a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@@ -182,6 +182,7 @@
 from .CreateAttributeIndex import CreateAttributeIndex
 from .DropGeometry import DropGeometry
 from .BasicStatistics import BasicStatisticsForField
+from .Heatmap import Heatmap
 
 pluginPath = os.path.normpath(os.path.join(
     os.path.split(os.path.dirname(__file__))[0], os.pardir))
@@ -246,7 +247,7 @@ def __init__(self):
                         RemoveNullGeometry(), ExtractByExpression(), ExtendLines(),
                         ExtractSpecificNodes(), GeometryByExpression(), SnapGeometriesToLayer(),
                         PoleOfInaccessibility(), CreateAttributeIndex(), DropGeometry(),
-                        BasicStatisticsForField(), RasterCalculator()
+                        BasicStatisticsForField(), RasterCalculator(), Heatmap()
                         ]
 
         if hasMatplotlib:

diff --git a/python/plugins/processing/images/heatmap.png b/python/plugins/processing/images/heatmap.png