Python core.QgsProcessingUtils类代码示例

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)

        writer = self.getOutputFromName(
            self.OUTPUT_LAYER).getVectorWriter(layer.fields(), QgsWkbTypes.LineString, layer.crs(), context)

        distance = self.getParameterValue(self.DISTANCE)
        segments = int(self.getParameterValue(self.SEGMENTS))
        join_style = self.getParameterValue(self.JOIN_STYLE) + 1
        miter_limit = self.getParameterValue(self.MITRE_LIMIT)

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)

        for current, input_feature in enumerate(features):
            output_feature = input_feature
            input_geometry = input_feature.geometry()
            if input_geometry:
                output_geometry = input_geometry.offsetCurve(distance, segments, join_style, miter_limit)
                if not output_geometry:
                    raise GeoAlgorithmExecutionException(
                        self.tr('Error calculating line offset'))

                output_feature.setGeometry(output_geometry)

            writer.addFeature(output_feature)
            feedback.setProgress(int(current * total))

        del writer

    def test_check_validity(self):
        """Test that the output invalid contains the error reason"""

        polygon_layer = self._make_layer('Polygon')
        self.assertTrue(polygon_layer.startEditing())
        f = QgsFeature(polygon_layer.fields())
        f.setAttributes([1])
        # Flake!
        f.setGeometry(QgsGeometry.fromWkt(
            'POLYGON ((0 0, 2 2, 0 2, 2 0, 0 0))'))
        self.assertTrue(f.isValid())
        f2 = QgsFeature(polygon_layer.fields())
        f2.setAttributes([1])
        f2.setGeometry(QgsGeometry.fromWkt(
            'POLYGON((1.1 1.1, 1.1 2.1, 2.1 2.1, 2.1 1.1, 1.1 1.1))'))
        self.assertTrue(f2.isValid())
        self.assertTrue(polygon_layer.addFeatures([f, f2]))
        polygon_layer.commitChanges()
        polygon_layer.rollBack()
        self.assertEqual(polygon_layer.featureCount(), 2)

        QgsProject.instance().addMapLayers([polygon_layer])

        alg = self.registry.createAlgorithmById('qgis:checkvalidity')

        context = QgsProcessingContext()
        context.setProject(QgsProject.instance())
        feedback = ConsoleFeedBack()

        self.assertIsNotNone(alg)
        parameters = {}
        parameters['INPUT_LAYER'] = polygon_layer.id()
        parameters['VALID_OUTPUT'] = 'memory:'
        parameters['INVALID_OUTPUT'] = 'memory:'
        parameters['ERROR_OUTPUT'] = 'memory:'

        # QGIS method
        parameters['METHOD'] = 1
        ok, results = execute(
            alg, parameters, context=context, feedback=feedback)
        self.assertTrue(ok)
        invalid_layer = QgsProcessingUtils.mapLayerFromString(
            results['INVALID_OUTPUT'], context)
        self.assertEqual(invalid_layer.fields().names()[-1], '_errors')
        self.assertEqual(invalid_layer.featureCount(), 1)
        f = next(invalid_layer.getFeatures())
        self.assertEqual(f.attributes(), [
                         1, 'segments 0 and 2 of line 0 intersect at 1, 1'])

        # GEOS method
        parameters['METHOD'] = 2
        ok, results = execute(
            alg, parameters, context=context, feedback=feedback)
        self.assertTrue(ok)
        invalid_layer = QgsProcessingUtils.mapLayerFromString(
            results['INVALID_OUTPUT'], context)
        self.assertEqual(invalid_layer.fields().names()[-1], '_errors')
        self.assertEqual(invalid_layer.featureCount(), 1)
        f = next(invalid_layer.getFeatures())
        self.assertEqual(f.attributes(), [1, 'Self-intersection'])

    def getAsString(self, value):
        if self.datatype == dataobjects.TYPE_RASTER:
            if isinstance(value, QgsRasterLayer):
                return str(value.dataProvider().dataSourceUri())
            else:
                s = str(value)
                layers = QgsProcessingUtils.compatibleRasterLayers(QgsProject.instance())
                for layer in layers:
                    if layer.name() == s:
                        return str(layer.dataProvider().dataSourceUri())
                return s

        if self.datatype == dataobjects.TYPE_FILE:
            return str(value)
        else:
            if isinstance(value, QgsVectorLayer):
                return str(value.source())
            else:
                s = str(value)
                if self.datatype != dataobjects.TYPE_VECTOR_ANY:
                    layers = QgsProcessingUtils.compatibleVectorLayers(QgsProject.instance(), [self.datatype], False)
                else:
                    layers = QgsProcessingUtils.compatibleVectorLayers(QgsProject.instance(), [], False)
                for layer in layers:
                    if layer.name() == s:
                        return str(layer.source())
                return s

    def getDefaultCellsize(self, parameters, context):
        cellsize = 0
        for param in self.parameterDefinitions():
            if param.name() in parameters:
                value = parameters[param.name()]
                if isinstance(param, ParameterRaster):
                    if isinstance(value, QgsRasterLayer):
                        layer = value
                    else:
                        layer = QgsProcessingUtils.mapLayerFromString(value, context)
                    cellsize = max(cellsize, (layer.extent().xMaximum() -
                                              layer.extent().xMinimum()) /
                                   layer.width())
                elif isinstance(param, ParameterMultipleInput):

                    layers = value.split(';')
                    for layername in layers:
                        layer = QgsProcessingUtils.mapLayerFromString(layername, context)
                        if isinstance(layer, QgsRasterLayer):
                            cellsize = max(cellsize, (
                                layer.extent().xMaximum() -
                                layer.extent().xMinimum()) /
                                layer.width())

        if cellsize == 0:
            cellsize = 1
        return cellsize

    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)

        output = self.getOutputFromName(self.OUTPUT)
        valuesField = layer.fields().lookupField(valuesFieldName)
        categoriesField = layer.fields().lookupField(categoriesFieldName)

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        values = {}
        for current, feat in enumerate(features):
            feedback.setProgress(int(current * total))
            attrs = feat.attributes()
            try:
                value = float(attrs[valuesField])
                cat = str(attrs[categoriesField])
                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)
        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)

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)

        fields = layer.fields()
        fields.append(QgsField('node_index', QVariant.Int))
        fields.append(QgsField('distance', QVariant.Double))
        fields.append(QgsField('angle', QVariant.Double))

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields, QgsWkbTypes.Point, layer.crs(), context)

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        for current, f in enumerate(features):
            input_geometry = f.geometry()
            if not input_geometry:
                writer.addFeature(f)
            else:
                points = vector.extractPoints(input_geometry)

                for i, point in enumerate(points):
                    distance = input_geometry.distanceToVertex(i)
                    angle = math.degrees(input_geometry.angleAtVertex(i))
                    attrs = f.attributes()
                    attrs.append(i)
                    attrs.append(distance)
                    attrs.append(angle)
                    output_feature = QgsFeature()
                    output_feature.setAttributes(attrs)
                    output_feature.setGeometry(QgsGeometry.fromPoint(point))
                    writer.addFeature(output_feature)

            feedback.setProgress(int(current * total))

        del writer

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
        reference_layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.REFERENCE_LAYER), context)
        tolerance = self.getParameterValue(self.TOLERANCE)
        mode = self.getParameterValue(self.BEHAVIOR)

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields(), layer.wkbType(), layer.crs(),
                                                                     context)

        features = QgsProcessingUtils.getFeatures(layer, context)

        self.processed = 0
        self.feedback = feedback
        self.total = 100.0 / QgsProcessingUtils.featureCount(layer, context)

        if self.getParameterValue(self.INPUT) != self.getParameterValue(self.REFERENCE_LAYER):
            snapper = QgsGeometrySnapper(reference_layer)
            snapper.featureSnapped.connect(self.featureSnapped)
            snapped_features = snapper.snapFeatures(features, tolerance, mode)
            for f in snapped_features:
                writer.addFeature(QgsFeature(f))
        else:
            # snapping internally
            snapper = QgsInternalGeometrySnapper(tolerance, mode)
            processed = 0
            for f in features:
                out_feature = f
                out_feature.setGeometry(snapper.snapFeature(f))
                writer.addFeature(out_feature)
                processed += 1
                feedback.setProgress(processed * self.total)

        del writer

    def regularMatrix(self, context, inLayer, inField, targetLayer, targetField,
                      nPoints, feedback):
        index = QgsProcessingUtils.createSpatialIndex(targetLayer, context)

        inIdx = inLayer.fields().lookupField(inField)

        distArea = QgsDistanceArea()

        first = True
        features = QgsProcessingUtils.getFeatures(inLayer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(inLayer, context)
        for current, inFeat in enumerate(features):
            inGeom = inFeat.geometry()
            inID = str(inFeat.attributes()[inIdx])
            featList = index.nearestNeighbor(inGeom.asPoint(), nPoints)
            if first:
                first = False
                data = ['ID']
                for i in range(len(featList)):
                    data.append('DIST_{0}'.format(i + 1))
                self.writer.addRecord(data)

            data = [inID]
            for i in featList:
                request = QgsFeatureRequest().setFilterFid(i)
                outFeat = next(targetLayer.getFeatures(request))
                outGeom = outFeat.geometry()
                dist = distArea.measureLine(inGeom.asPoint(),
                                            outGeom.asPoint())
                data.append(str(float(dist)))
            self.writer.addRecord(data)

            feedback.setProgress(int(current * total))

    def processAlgorithm(self, parameters, context, feedback):
        inLayer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
        inField = self.getParameterValue(self.INPUT_FIELD)
        targetLayer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.TARGET_LAYER), context)
        targetField = self.getParameterValue(self.TARGET_FIELD)
        matType = self.getParameterValue(self.MATRIX_TYPE)
        nPoints = self.getParameterValue(self.NEAREST_POINTS)

        outputFile = self.getOutputFromName(self.DISTANCE_MATRIX)

        if nPoints < 1:
            nPoints = QgsProcessingUtils.featureCount(targetLayer, context)

        self.writer = outputFile.getTableWriter([])

        if matType == 0:
            # Linear distance matrix
            self.linearMatrix(context, inLayer, inField, targetLayer, targetField,
                              matType, nPoints, feedback)
        elif matType == 1:
            # Standard distance matrix
            self.regularMatrix(context, inLayer, inField, targetLayer, targetField,
                               nPoints, feedback)
        elif matType == 2:
            # Summary distance matrix
            self.linearMatrix(context, inLayer, inField, targetLayer, targetField,
                              matType, nPoints, feedback)

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields(), QgsWkbTypes.Polygon,
                                                                     layer.crs(), context)

        outFeat = QgsFeature()
        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        for current, f in enumerate(features):
            outGeomList = []
            if f.geometry().isMultipart():
                outGeomList = f.geometry().asMultiPolyline()
            else:
                outGeomList.append(f.geometry().asPolyline())

            polyGeom = self.removeBadLines(outGeomList)
            if len(polyGeom) != 0:
                outFeat.setGeometry(QgsGeometry.fromPolygon(polyGeom))
                attrs = f.attributes()
                outFeat.setAttributes(attrs)
                writer.addFeature(outFeat)

            feedback.setProgress(int(current * total))

        del writer

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
        iterations = self.getParameterValue(self.ITERATIONS)
        offset = self.getParameterValue(self.OFFSET)
        max_angle = self.getParameterValue(self.MAX_ANGLE)

        writer = self.getOutputFromName(
            self.OUTPUT_LAYER).getVectorWriter(layer.fields(), layer.wkbType(), layer.crs(), context)

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)

        for current, input_feature in enumerate(features):
            output_feature = input_feature
            if input_feature.geometry():
                output_geometry = input_feature.geometry().smooth(iterations, offset, -1, max_angle)
                if not output_geometry:
                    raise GeoAlgorithmExecutionException(
                        self.tr('Error smoothing geometry'))

                output_feature.setGeometry(output_geometry)

            writer.addFeature(output_feature)
            feedback.setProgress(int(current * total))

        del writer

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
        crsId = self.getParameterValue(self.TARGET_CRS)
        targetCrs = QgsCoordinateReferenceSystem()
        targetCrs.createFromUserInput(crsId)

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields(), layer.wkbType(),
                                                                     targetCrs, context)

        layerCrs = layer.crs()
        crsTransform = QgsCoordinateTransform(layerCrs, targetCrs)

        outFeat = QgsFeature()
        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        for current, f in enumerate(features):
            geom = f.geometry()
            geom.transform(crsTransform)
            outFeat.setGeometry(geom)
            outFeat.setAttributes(f.attributes())
            writer.addFeature(outFeat)

            feedback.setProgress(int(current * total))

        del writer

        self.crs = targetCrs

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)

        fields = layer.fields()
        fields.append(QgsField('node_pos', QVariant.Int))
        fields.append(QgsField('node_index', QVariant.Int))
        fields.append(QgsField('distance', QVariant.Double))
        fields.append(QgsField('angle', QVariant.Double))

        writer = self.getOutputFromName(
            self.OUTPUT_LAYER).getVectorWriter(fields, QgsWkbTypes.Point, layer.crs(), context)

        node_indices_string = self.getParameterValue(self.NODES)
        indices = []
        for node in node_indices_string.split(','):
            try:
                indices.append(int(node))
            except:
                raise GeoAlgorithmExecutionException(
                    self.tr('\'{}\' is not a valid node index').format(node))

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / layer.featureCount() if layer.featureCount() else 0

        for current, f in enumerate(features):

            input_geometry = f.geometry()
            if not input_geometry:
                writer.addFeature(f, QgsFeatureSink.FastInsert)
            else:
                total_nodes = input_geometry.geometry().nCoordinates()

                for node in indices:
                    if node < 0:
                        node_index = total_nodes + node
                    else:
                        node_index = node

                    if node_index < 0 or node_index >= total_nodes:
                        continue

                    distance = input_geometry.distanceToVertex(node_index)
                    angle = math.degrees(input_geometry.angleAtVertex(node_index))

                    output_feature = QgsFeature()
                    attrs = f.attributes()
                    attrs.append(node)
                    attrs.append(node_index)
                    attrs.append(distance)
                    attrs.append(angle)
                    output_feature.setAttributes(attrs)

                    point = input_geometry.vertexAt(node_index)
                    output_feature.setGeometry(QgsGeometry.fromPoint(point))

                    writer.addFeature(output_feature, QgsFeatureSink.FastInsert)

            feedback.setProgress(int(current * total))

        del writer

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)

        fields = layer.fields()

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields, layer.wkbType(), layer.crs(), context)

        features = QgsProcessingUtils.getFeatures(layer, context)

        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        geoms = dict()
        for current, f in enumerate(features):
            geoms[f.id()] = f.geometry()
            feedback.setProgress(int(current * total))

        cleaned = dict(geoms)

        for i, g in list(geoms.items()):
            for j in list(cleaned.keys()):
                if i == j or i not in cleaned:
                    continue
                if g.isGeosEqual(cleaned[j]):
                    del cleaned[j]

        total = 100.0 / len(cleaned)
        request = QgsFeatureRequest().setFilterFids(list(cleaned.keys()))
        for current, f in enumerate(layer.getFeatures(request)):
            writer.addFeature(f)
            feedback.setProgress(int(current * total))

        del writer

    def processAlgorithm(self, parameters, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
        fieldName = self.getParameterValue(self.FIELD)
        idx = layer.fields().lookupField(fieldName)

        fields = layer.fields()
        fields[idx] = QgsField(fieldName, QVariant.Double, '', 24, 15)

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields, layer.wkbType(), layer.crs(), context)

        features = QgsProcessingUtils.getFeatures(layer, context)

        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        for current, f in enumerate(features):
            value = f[idx]
            try:
                if '%' in value:
                    f[idx] = float(value.replace('%', '')) / 100.0
                else:
                    f[idx] = float(value)
            except:
                f[idx] = None

            writer.addFeature(f)
            feedback.setProgress(int(current * total))

        del writer