Port Stats by Category to new API

Improvements: - keep original field type and name for category field - add unit test
2025-02-27 00:33:48 -05:00 · 2017-08-05 07:01:06 +10:00 · 2017-08-05 07:01:06 +10:00 · b93be39c24
commit b93be39c24
parent adda744576
5 changed files with 153 additions and 32 deletions
--- a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
+++ b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@ -132,6 +132,7 @@ from .SnapGeometries import SnapGeometriesToLayer
 from .SpatialiteExecuteSQL import SpatialiteExecuteSQL
 from .SpatialIndex import SpatialIndex
 from .SplitWithLines import SplitWithLines
+from .StatisticsByCategories import StatisticsByCategories
 from .SumLines import SumLines
 from .SymmetricalDifference import SymmetricalDifference
 from .TextToFloat import TextToFloat
@ -149,7 +150,6 @@ from .ZonalStatistics import ZonalStatistics
 # from .SelectByLocation import SelectByLocation
 # from .SpatialJoin import SpatialJoin
 # from .GeometryConvert import GeometryConvert
-# from .StatisticsByCategories import StatisticsByCategories
 # from .FieldsCalculator import FieldsCalculator
 # from .FieldPyculator import FieldsPyculator
 # from .PointsDisplacement import PointsDisplacement
@ -190,7 +190,7 @@ class QGISAlgorithmProvider(QgsProcessingProvider):
        #         SpatialJoin(),
        #         GeometryConvert(), FieldsCalculator(),
        #         FieldsPyculator(),
-        #         StatisticsByCategories(),
+        #
        #         RasterLayerStatistics(), PointsDisplacement(),
        #         PointsFromPolygons(),
        #         PointsFromLines(),
@ -298,6 +298,7 @@ class QGISAlgorithmProvider(QgsProcessingProvider):
                SpatialiteExecuteSQL(),
                SpatialIndex(),
                SplitWithLines(),
+                StatisticsByCategories(),
                SumLines(),
                SymmetricalDifference(),
                TextToFloat(),
--- a/python/plugins/processing/algs/qgis/StatisticsByCategories.py
+++ b/python/plugins/processing/algs/qgis/StatisticsByCategories.py
@ -26,19 +26,24 @@ __copyright__ = '(C) 2012, Victor Olaya'

 __revision__ = '$Format:%H$'

-from qgis.core import (QgsApplication,
-                       QgsFeatureSink,
+from qgis.core import (QgsProcessingParameterFeatureSource,
                       QgsStatisticalSummary,
-                       QgsProcessingUtils)
-from processing.core.outputs import OutputTable
+                       QgsFeatureRequest,
+                       QgsProcessingParameterField,
+                       QgsProcessingParameterFeatureSink,
+                       QgsFields,
+                       QgsField,
+                       QgsWkbTypes,
+                       QgsCoordinateReferenceSystem,
+                       QgsFeature,
+                       QgsFeatureSink)
+from qgis.PyQt.QtCore import QVariant
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterVector
-from processing.core.parameters import ParameterTableField


 class StatisticsByCategories(QgisAlgorithm):

-    INPUT_LAYER = 'INPUT_LAYER'
+    INPUT = 'INPUT'
    VALUES_FIELD_NAME = 'VALUES_FIELD_NAME'
    CATEGORIES_FIELD_NAME = 'CATEGORIES_FIELD_NAME'
    OUTPUT = 'OUTPUT'
@ -50,16 +55,16 @@ class StatisticsByCategories(QgisAlgorithm):
        super().__init__()

    def initAlgorithm(self, config=None):
-        self.addParameter(ParameterVector(self.INPUT_LAYER,
-                                          self.tr('Input vector layer')))
-        self.addParameter(ParameterTableField(self.VALUES_FIELD_NAME,
-                                              self.tr('Field to calculate statistics on'),
-                                              self.INPUT_LAYER, ParameterTableField.DATA_TYPE_NUMBER))
-        self.addParameter(ParameterTableField(self.CATEGORIES_FIELD_NAME,
-                                              self.tr('Field with categories'),
-                                              self.INPUT_LAYER, ParameterTableField.DATA_TYPE_ANY))
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
+                                                              self.tr('Input vector layer')))
+        self.addParameter(QgsProcessingParameterField(self.VALUES_FIELD_NAME,
+                                                      self.tr('Field to calculate statistics on'),
+                                                      parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Numeric))
+        self.addParameter(QgsProcessingParameterField(self.CATEGORIES_FIELD_NAME,
+                                                      self.tr('Field with categories'),
+                                                      parentLayerParameterName=self.INPUT, type=QgsProcessingParameterField.Any))

-        self.addOutput(OutputTable(self.OUTPUT, self.tr('Statistics by category')))
+        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Statistics by category')))

    def name(self):
        return 'statisticsbycategories'
@ -68,36 +73,51 @@ class StatisticsByCategories(QgisAlgorithm):
        return self.tr('Statistics by categories')

    def processAlgorithm(self, parameters, context, feedback):
-        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
-        valuesFieldName = self.getParameterValue(self.VALUES_FIELD_NAME)
-        categoriesFieldName = self.getParameterValue(self.CATEGORIES_FIELD_NAME)
+        source = self.parameterAsSource(parameters, self.INPUT, context)
+        value_field_name = self.parameterAsString(parameters, self.VALUES_FIELD_NAME, context)
+        category_field_name = self.parameterAsString(parameters, self.CATEGORIES_FIELD_NAME, context)

-        output = self.getOutputFromName(self.OUTPUT)
-        valuesField = layer.fields().lookupField(valuesFieldName)
-        categoriesField = layer.fields().lookupField(categoriesFieldName)
+        value_field_index = source.fields().lookupField(value_field_name)
+        category_field_index = source.fields().lookupField(category_field_name)

-        features = QgsProcessingUtils.getFeatures(layer, context)
-        total = 100.0 / layer.featureCount() if layer.featureCount() else 0
+        features = source.getFeatures(QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry))
+        total = 100.0 / source.featureCount() if source.featureCount() else 0
        values = {}
        for current, feat in enumerate(features):
+            if feedback.isCanceled():
+                break
+
            feedback.setProgress(int(current * total))
            attrs = feat.attributes()
            try:
-                value = float(attrs[valuesField])
-                cat = str(attrs[categoriesField])
+                value = float(attrs[value_field_index])
+                cat = attrs[category_field_index]
                if cat not in values:
                    values[cat] = []
                values[cat].append(value)
            except:
                pass

-        fields = ['category', 'min', 'max', 'mean', 'stddev', 'sum', 'count']
-        writer = output.getTableWriter(fields)
+        fields = QgsFields()
+        fields.append(source.fields().at(category_field_index))
+        fields.append(QgsField('min', QVariant.Double))
+        fields.append(QgsField('max', QVariant.Double))
+        fields.append(QgsField('mean', QVariant.Double))
+        fields.append(QgsField('stddev', QVariant.Double))
+        fields.append(QgsField('sum', QVariant.Double))
+        fields.append(QgsField('count', QVariant.Int))
+
+        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
+                                               fields, QgsWkbTypes.NoGeometry, QgsCoordinateReferenceSystem())
+
        stat = QgsStatisticalSummary(QgsStatisticalSummary.Min | QgsStatisticalSummary.Max |
                                     QgsStatisticalSummary.Mean | QgsStatisticalSummary.StDevSample |
                                     QgsStatisticalSummary.Sum | QgsStatisticalSummary.Count)

        for (cat, v) in list(values.items()):
            stat.calculate(v)
-            record = [cat, stat.min(), stat.max(), stat.mean(), stat.sampleStDev(), stat.sum(), stat.count()]
-            writer.addRecord(record)
+            f = QgsFeature()
+            f.setAttributes([cat, stat.min(), stat.max(), stat.mean(), stat.sampleStDev(), stat.sum(), stat.count()])
+            sink.addFeature(f, QgsFeatureSink.FastInsert)
+
+        return {self.OUTPUT: dest_id}
--- a/python/plugins/processing/tests/testdata/expected/stats_by_category.gfs
+++ b/python/plugins/processing/tests/testdata/expected/stats_by_category.gfs
@ -0,0 +1,45 @@
+<GMLFeatureClassList>
+  <GMLFeatureClass>
+    <Name>stats_by_category</Name>
+    <ElementPath>stats_by_category</ElementPath>
+    <GeometryType>100</GeometryType>
+    <DatasetSpecificInfo>
+      <FeatureCount>3</FeatureCount>
+    </DatasetSpecificInfo>
+    <PropertyDefn>
+      <Name>id2</Name>
+      <ElementPath>id2</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>min</Name>
+      <ElementPath>min</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>max</Name>
+      <ElementPath>max</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>mean</Name>
+      <ElementPath>mean</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>stddev</Name>
+      <ElementPath>stddev</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>sum</Name>
+      <ElementPath>sum</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>count</Name>
+      <ElementPath>count</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+  </GMLFeatureClass>
+</GMLFeatureClassList>
--- a/python/plugins/processing/tests/testdata/expected/stats_by_category.gml
+++ b/python/plugins/processing/tests/testdata/expected/stats_by_category.gml
@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation=""
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy><gml:null>missing</gml:null></gml:boundedBy>
+                                                                                                                                                                                                                                                                                                
+  <gml:featureMember>
+    <ogr:stats_by_category fid="stats_by_category.0">
+      <ogr:id2>2</ogr:id2>
+      <ogr:min>1</ogr:min>
+      <ogr:max>4</ogr:max>
+      <ogr:mean>2.5</ogr:mean>
+      <ogr:stddev>2.12132034355964</ogr:stddev>
+      <ogr:sum>5</ogr:sum>
+      <ogr:count>2</ogr:count>
+    </ogr:stats_by_category>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:stats_by_category fid="stats_by_category.1">
+      <ogr:id2>1</ogr:id2>
+      <ogr:min>2</ogr:min>
+      <ogr:max>5</ogr:max>
+      <ogr:mean>3.5</ogr:mean>
+      <ogr:stddev>2.12132034355964</ogr:stddev>
+      <ogr:sum>7</ogr:sum>
+      <ogr:count>2</ogr:count>
+    </ogr:stats_by_category>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:stats_by_category fid="stats_by_category.2">
+      <ogr:id2>0</ogr:id2>
+      <ogr:min>3</ogr:min>
+      <ogr:max>9</ogr:max>
+      <ogr:mean>6.6</ogr:mean>
+      <ogr:stddev>2.30217288664427</ogr:stddev>
+      <ogr:sum>33</ogr:sum>
+      <ogr:count>5</ogr:count>
+    </ogr:stats_by_category>
+  </gml:featureMember>
+</ogr:FeatureCollection>
--- a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
+++ b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@ -2489,6 +2489,19 @@ tests:
        name: expected/single_to_multi.gml
        type: vector

+  - algorithm: qgis:statisticsbycategories
+    name: stats by category
+    params:
+      VALUES_FIELD_NAME: id
+      CATEGORIES_FIELD_NAME: id2
+      INPUT:
+        name: points.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/stats_by_category.gml
+        type: vector
+
 #  - algorithm: qgis:zonalstatistics
 #    name: simple zonal statistics
 #    params: