bool QgsVectorDataProvider::empty() const { QgsFeature f; QgsFeatureRequest request; request.setNoAttributes(); request.setFlags( QgsFeatureRequest::NoGeometry ); request.setLimit( 1 ); if ( getFeatures( request ).nextFeature( f ) ) return false; else return true; }
QgsRectangle QgsFeatureSource::sourceExtent() const { QgsRectangle r; QgsFeatureRequest req; req.setNoAttributes(); QgsFeatureIterator it = getFeatures( req ); QgsFeature f; while ( it.nextFeature( f ) ) { if ( f.hasGeometry() ) r.combineExtentWith( f.geometry().boundingBox() ); } return r; }
int QgsZonalStatistics::calculateStatistics( QgsFeedback *feedback ) { if ( !mPolygonLayer || mPolygonLayer->geometryType() != QgsWkbTypes::PolygonGeometry ) { return 1; } QgsVectorDataProvider *vectorProvider = mPolygonLayer->dataProvider(); if ( !vectorProvider ) { return 2; } if ( !mRasterInterface ) { return 3; } if ( mRasterInterface->bandCount() < mRasterBand ) { return 4; } //get geometry info about raster layer int nCellsXProvider = mRasterInterface->xSize(); int nCellsYProvider = mRasterInterface->ySize(); QgsRectangle rasterBBox = mRasterInterface->extent(); //add the new fields to the provider QList<QgsField> newFieldList; QString countFieldName; if ( mStatistics & QgsZonalStatistics::Count ) { countFieldName = getUniqueFieldName( mAttributePrefix + "count", newFieldList ); QgsField countField( countFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( countField ); } QString sumFieldName; if ( mStatistics & QgsZonalStatistics::Sum ) { sumFieldName = getUniqueFieldName( mAttributePrefix + "sum", newFieldList ); QgsField sumField( sumFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( sumField ); } QString meanFieldName; if ( mStatistics & QgsZonalStatistics::Mean ) { meanFieldName = getUniqueFieldName( mAttributePrefix + "mean", newFieldList ); QgsField meanField( meanFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( meanField ); } QString medianFieldName; if ( mStatistics & QgsZonalStatistics::Median ) { medianFieldName = getUniqueFieldName( mAttributePrefix + "median", newFieldList ); QgsField medianField( medianFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( medianField ); } QString stdevFieldName; if ( mStatistics & QgsZonalStatistics::StDev ) { stdevFieldName = getUniqueFieldName( mAttributePrefix + "stdev", newFieldList ); QgsField stdField( stdevFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( stdField ); } QString minFieldName; if ( mStatistics & QgsZonalStatistics::Min ) { minFieldName = getUniqueFieldName( mAttributePrefix + "min", newFieldList ); QgsField minField( minFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( minField ); } QString maxFieldName; if ( mStatistics & QgsZonalStatistics::Max ) { maxFieldName = getUniqueFieldName( mAttributePrefix + "max", newFieldList ); QgsField maxField( maxFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( maxField ); } QString rangeFieldName; if ( mStatistics & QgsZonalStatistics::Range ) { rangeFieldName = getUniqueFieldName( mAttributePrefix + "range", newFieldList ); QgsField rangeField( rangeFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( rangeField ); } QString minorityFieldName; if ( mStatistics & QgsZonalStatistics::Minority ) { minorityFieldName = getUniqueFieldName( mAttributePrefix + "minority", newFieldList ); QgsField minorityField( minorityFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( minorityField ); } QString majorityFieldName; if ( mStatistics & QgsZonalStatistics::Majority ) { majorityFieldName = getUniqueFieldName( mAttributePrefix + "majority", newFieldList ); QgsField majField( majorityFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( majField ); } QString varietyFieldName; if ( mStatistics & QgsZonalStatistics::Variety ) { varietyFieldName = getUniqueFieldName( mAttributePrefix + "variety", newFieldList ); QgsField varietyField( varietyFieldName, QVariant::Int, QStringLiteral( "int" ) ); newFieldList.push_back( varietyField ); } QString varianceFieldName; if ( mStatistics & QgsZonalStatistics::Variance ) { varianceFieldName = getUniqueFieldName( mAttributePrefix + "variance", newFieldList ); QgsField varianceField( varianceFieldName, QVariant::Double, QStringLiteral( "double precision" ) ); newFieldList.push_back( varianceField ); } vectorProvider->addAttributes( newFieldList ); //index of the new fields int countIndex = mStatistics & QgsZonalStatistics::Count ? vectorProvider->fieldNameIndex( countFieldName ) : -1; int sumIndex = mStatistics & QgsZonalStatistics::Sum ? vectorProvider->fieldNameIndex( sumFieldName ) : -1; int meanIndex = mStatistics & QgsZonalStatistics::Mean ? vectorProvider->fieldNameIndex( meanFieldName ) : -1; int medianIndex = mStatistics & QgsZonalStatistics::Median ? vectorProvider->fieldNameIndex( medianFieldName ) : -1; int stdevIndex = mStatistics & QgsZonalStatistics::StDev ? vectorProvider->fieldNameIndex( stdevFieldName ) : -1; int minIndex = mStatistics & QgsZonalStatistics::Min ? vectorProvider->fieldNameIndex( minFieldName ) : -1; int maxIndex = mStatistics & QgsZonalStatistics::Max ? vectorProvider->fieldNameIndex( maxFieldName ) : -1; int rangeIndex = mStatistics & QgsZonalStatistics::Range ? vectorProvider->fieldNameIndex( rangeFieldName ) : -1; int minorityIndex = mStatistics & QgsZonalStatistics::Minority ? vectorProvider->fieldNameIndex( minorityFieldName ) : -1; int majorityIndex = mStatistics & QgsZonalStatistics::Majority ? vectorProvider->fieldNameIndex( majorityFieldName ) : -1; int varietyIndex = mStatistics & QgsZonalStatistics::Variety ? vectorProvider->fieldNameIndex( varietyFieldName ) : -1; int varianceIndex = mStatistics & QgsZonalStatistics::Variance ? vectorProvider->fieldNameIndex( varianceFieldName ) : -1; if ( ( mStatistics & QgsZonalStatistics::Count && countIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Sum && sumIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Mean && meanIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Median && medianIndex == -1 ) || ( mStatistics & QgsZonalStatistics::StDev && stdevIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Min && minIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Max && maxIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Range && rangeIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Minority && minorityIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Majority && majorityIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Variety && varietyIndex == -1 ) || ( mStatistics & QgsZonalStatistics::Variance && varianceIndex == -1 ) ) { //failed to create a required field return 8; } //progress dialog long featureCount = vectorProvider->featureCount(); //iterate over each polygon QgsFeatureRequest request; request.setNoAttributes(); request.setDestinationCrs( mRasterCrs, QgsProject::instance()->transformContext() ); QgsFeatureIterator fi = vectorProvider->getFeatures( request ); QgsFeature f; bool statsStoreValues = ( mStatistics & QgsZonalStatistics::Median ) || ( mStatistics & QgsZonalStatistics::StDev ) || ( mStatistics & QgsZonalStatistics::Variance ); bool statsStoreValueCount = ( mStatistics & QgsZonalStatistics::Minority ) || ( mStatistics & QgsZonalStatistics::Majority ); FeatureStats featureStats( statsStoreValues, statsStoreValueCount ); int featureCounter = 0; QgsChangedAttributesMap changeMap; while ( fi.nextFeature( f ) ) { if ( feedback && feedback->isCanceled() ) { break; } if ( feedback ) { feedback->setProgress( 100.0 * static_cast< double >( featureCounter ) / featureCount ); } if ( !f.hasGeometry() ) { ++featureCounter; continue; } QgsGeometry featureGeometry = f.geometry(); QgsRectangle featureRect = featureGeometry.boundingBox().intersect( rasterBBox ); if ( featureRect.isEmpty() ) { ++featureCounter; continue; } int nCellsX, nCellsY; QgsRectangle rasterBlockExtent; QgsRasterAnalysisUtils::cellInfoForBBox( rasterBBox, featureRect, mCellSizeX, mCellSizeY, nCellsX, nCellsY, nCellsXProvider, nCellsYProvider, rasterBlockExtent ); featureStats.reset(); QgsRasterAnalysisUtils::statisticsFromMiddlePointTest( mRasterInterface, mRasterBand, featureGeometry, nCellsX, nCellsY, mCellSizeX, mCellSizeY, rasterBlockExtent, [ &featureStats ]( double value ) { featureStats.addValue( value ); } ); if ( featureStats.count <= 1 ) { //the cell resolution is probably larger than the polygon area. We switch to precise pixel - polygon intersection in this case featureStats.reset(); QgsRasterAnalysisUtils::statisticsFromPreciseIntersection( mRasterInterface, mRasterBand, featureGeometry, nCellsX, nCellsY, mCellSizeX, mCellSizeY, rasterBlockExtent, [ &featureStats ]( double value, double weight ) { featureStats.addValue( value, weight ); } ); } //write the statistics value to the vector data provider QgsAttributeMap changeAttributeMap; if ( mStatistics & QgsZonalStatistics::Count ) changeAttributeMap.insert( countIndex, QVariant( featureStats.count ) ); if ( mStatistics & QgsZonalStatistics::Sum ) changeAttributeMap.insert( sumIndex, QVariant( featureStats.sum ) ); if ( featureStats.count > 0 ) { double mean = featureStats.sum / featureStats.count; if ( mStatistics & QgsZonalStatistics::Mean ) changeAttributeMap.insert( meanIndex, QVariant( mean ) ); if ( mStatistics & QgsZonalStatistics::Median ) { std::sort( featureStats.values.begin(), featureStats.values.end() ); int size = featureStats.values.count(); bool even = ( size % 2 ) < 1; double medianValue; if ( even ) { medianValue = ( featureStats.values.at( size / 2 - 1 ) + featureStats.values.at( size / 2 ) ) / 2; } else //odd { medianValue = featureStats.values.at( ( size + 1 ) / 2 - 1 ); } changeAttributeMap.insert( medianIndex, QVariant( medianValue ) ); } if ( mStatistics & QgsZonalStatistics::StDev || mStatistics & QgsZonalStatistics::Variance ) { double sumSquared = 0; for ( int i = 0; i < featureStats.values.count(); ++i ) { double diff = featureStats.values.at( i ) - mean; sumSquared += diff * diff; } double variance = sumSquared / featureStats.values.count(); if ( mStatistics & QgsZonalStatistics::StDev ) { double stdev = std::pow( variance, 0.5 ); changeAttributeMap.insert( stdevIndex, QVariant( stdev ) ); } if ( mStatistics & QgsZonalStatistics::Variance ) changeAttributeMap.insert( varianceIndex, QVariant( variance ) ); } if ( mStatistics & QgsZonalStatistics::Min ) changeAttributeMap.insert( minIndex, QVariant( featureStats.min ) ); if ( mStatistics & QgsZonalStatistics::Max ) changeAttributeMap.insert( maxIndex, QVariant( featureStats.max ) ); if ( mStatistics & QgsZonalStatistics::Range ) changeAttributeMap.insert( rangeIndex, QVariant( featureStats.max - featureStats.min ) ); if ( mStatistics & QgsZonalStatistics::Minority || mStatistics & QgsZonalStatistics::Majority ) { QList<int> vals = featureStats.valueCount.values(); std::sort( vals.begin(), vals.end() ); if ( mStatistics & QgsZonalStatistics::Minority ) { double minorityKey = featureStats.valueCount.key( vals.first() ); changeAttributeMap.insert( minorityIndex, QVariant( minorityKey ) ); } if ( mStatistics & QgsZonalStatistics::Majority ) { double majKey = featureStats.valueCount.key( vals.last() ); changeAttributeMap.insert( majorityIndex, QVariant( majKey ) ); } } if ( mStatistics & QgsZonalStatistics::Variety ) changeAttributeMap.insert( varietyIndex, QVariant( featureStats.valueCount.count() ) ); } changeMap.insert( f.id(), changeAttributeMap ); ++featureCounter; } vectorProvider->changeAttributeValues( changeMap ); if ( feedback ) { feedback->setProgress( 100 ); } mPolygonLayer->updateFields(); if ( feedback && feedback->isCanceled() ) { return 9; } return 0; }
QgsFeatureIds QgsMapToolSelectUtils::getMatchingFeatures( QgsMapCanvas *canvas, const QgsGeometry &selectGeometry, bool doContains, bool singleSelect ) { QgsFeatureIds newSelectedFeatures; if ( selectGeometry.type() != QgsWkbTypes::PolygonGeometry ) return newSelectedFeatures; QgsVectorLayer *vlayer = QgsMapToolSelectUtils::getCurrentVectorLayer( canvas ); if ( !vlayer ) return newSelectedFeatures; // toLayerCoordinates will throw an exception for any 'invalid' points in // the rubber band. // For example, if you project a world map onto a globe using EPSG 2163 // and then click somewhere off the globe, an exception will be thrown. QgsGeometry selectGeomTrans = selectGeometry; try { QgsCoordinateTransform ct( canvas->mapSettings().destinationCrs(), vlayer->crs(), QgsProject::instance() ); if ( !ct.isShortCircuited() && selectGeomTrans.type() == QgsWkbTypes::PolygonGeometry ) { // convert add more points to the edges of the rectangle // improve transformation result QgsPolygonXY poly( selectGeomTrans.asPolygon() ); if ( poly.size() == 1 && poly.at( 0 ).size() == 5 ) { const QgsPolylineXY &ringIn = poly.at( 0 ); QgsPolygonXY newpoly( 1 ); newpoly[0].resize( 41 ); QgsPolylineXY &ringOut = newpoly[0]; ringOut[ 0 ] = ringIn.at( 0 ); int i = 1; for ( int j = 1; j < 5; j++ ) { QgsVector v( ( ringIn.at( j ) - ringIn.at( j - 1 ) ) / 10.0 ); for ( int k = 0; k < 9; k++ ) { ringOut[ i ] = ringOut[ i - 1 ] + v; i++; } ringOut[ i++ ] = ringIn.at( j ); } selectGeomTrans = QgsGeometry::fromPolygonXY( newpoly ); } } selectGeomTrans.transform( ct ); } catch ( QgsCsException &cse ) { Q_UNUSED( cse ); // catch exception for 'invalid' point and leave existing selection unchanged QgsDebugMsg( QStringLiteral( "Caught CRS exception " ) ); QgisApp::instance()->messageBar()->pushMessage( QObject::tr( "CRS Exception" ), QObject::tr( "Selection extends beyond layer's coordinate system" ), Qgis::Warning, QgisApp::instance()->messageTimeout() ); return newSelectedFeatures; } QgsDebugMsgLevel( "Selection layer: " + vlayer->name(), 3 ); QgsDebugMsgLevel( "Selection polygon: " + selectGeomTrans.asWkt(), 3 ); QgsDebugMsgLevel( "doContains: " + QString( doContains ? "T" : "F" ), 3 ); QgsRenderContext context = QgsRenderContext::fromMapSettings( canvas->mapSettings() ); context.expressionContext() << QgsExpressionContextUtils::layerScope( vlayer ); std::unique_ptr< QgsFeatureRenderer > r; if ( vlayer->renderer() ) { r.reset( vlayer->renderer()->clone() ); r->startRender( context, vlayer->fields() ); } QgsFeatureRequest request; request.setFilterRect( selectGeomTrans.boundingBox() ); request.setFlags( QgsFeatureRequest::ExactIntersect ); if ( r ) request.setSubsetOfAttributes( r->usedAttributes( context ), vlayer->fields() ); else request.setNoAttributes(); QgsFeatureIterator fit = vlayer->getFeatures( request ); QgsFeature f; QgsFeatureId closestFeatureId = 0; bool foundSingleFeature = false; double closestFeatureDist = std::numeric_limits<double>::max(); while ( fit.nextFeature( f ) ) { context.expressionContext().setFeature( f ); // make sure to only use features that are visible if ( r && !r->willRenderFeature( f, context ) ) continue; QgsGeometry g = f.geometry(); if ( doContains ) { if ( !selectGeomTrans.contains( g ) ) continue; } else { if ( !selectGeomTrans.intersects( g ) ) continue; } if ( singleSelect ) { foundSingleFeature = true; double distance = g.distance( selectGeomTrans ); if ( distance <= closestFeatureDist ) { closestFeatureDist = distance; closestFeatureId = f.id(); } } else { newSelectedFeatures.insert( f.id() ); } } if ( singleSelect && foundSingleFeature ) { newSelectedFeatures.insert( closestFeatureId ); } if ( r ) r->stopRender( context ); QgsDebugMsg( "Number of new selected features: " + QString::number( newSelectedFeatures.size() ) ); return newSelectedFeatures; }
QVariantMap QgsZonalHistogramAlgorithm::processAlgorithm( const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) { std::unique_ptr< QgsFeatureSource > zones( parameterAsSource( parameters, QStringLiteral( "INPUT_VECTOR" ), context ) ); if ( !zones ) throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT_VECTOR" ) ) ); long count = zones->featureCount(); double step = count > 0 ? 100.0 / count : 1; long current = 0; QList< double > uniqueValues; QMap< QgsFeatureId, QHash< double, qgssize > > featuresUniqueValues; // First loop through the zones to build up a list of unique values across all zones to determine sink fields list QgsFeatureRequest request; request.setNoAttributes(); if ( zones->sourceCrs() != mCrs ) { request.setDestinationCrs( mCrs, context.transformContext() ); } QgsFeatureIterator it = zones->getFeatures( request ); QgsFeature f; while ( it.nextFeature( f ) ) { if ( feedback && feedback->isCanceled() ) { break; } feedback->setProgress( current * step ); if ( !f.hasGeometry() ) { current++; continue; } QgsGeometry featureGeometry = f.geometry(); QgsRectangle featureRect = featureGeometry.boundingBox().intersect( mRasterExtent ); if ( featureRect.isEmpty() ) { current++; continue; } int nCellsX, nCellsY; QgsRectangle rasterBlockExtent; QgsRasterAnalysisUtils::cellInfoForBBox( mRasterExtent, featureRect, mCellSizeX, mCellSizeY, nCellsX, nCellsY, mNbCellsXProvider, mNbCellsYProvider, rasterBlockExtent ); QHash< double, qgssize > fUniqueValues; QgsRasterAnalysisUtils::statisticsFromMiddlePointTest( mRasterInterface.get(), mRasterBand, featureGeometry, nCellsX, nCellsY, mCellSizeX, mCellSizeY, rasterBlockExtent, [ &fUniqueValues]( double value ) { fUniqueValues[value]++; }, false ); if ( fUniqueValues.count() < 1 ) { // The cell resolution is probably larger than the polygon area. We switch to slower precise pixel - polygon intersection in this case // TODO: eventually deal with weight if needed QgsRasterAnalysisUtils::statisticsFromPreciseIntersection( mRasterInterface.get(), mRasterBand, featureGeometry, nCellsX, nCellsY, mCellSizeX, mCellSizeY, rasterBlockExtent, [ &fUniqueValues]( double value, double ) { fUniqueValues[value]++; }, false ); } for ( auto it = fUniqueValues.constBegin(); it != fUniqueValues.constEnd(); ++it ) { if ( uniqueValues.indexOf( it.key() ) == -1 ) { uniqueValues << it.key(); } featuresUniqueValues[f.id()][it.key()] += it.value(); } current++; } std::sort( uniqueValues.begin(), uniqueValues.end() ); QString fieldPrefix = parameterAsString( parameters, QStringLiteral( "COLUMN_PREFIX" ), context ); QgsFields newFields; for ( auto it = uniqueValues.constBegin(); it != uniqueValues.constEnd(); ++it ) { newFields.append( QgsField( QStringLiteral( "%1%2" ).arg( fieldPrefix, mHasNoDataValue && *it == mNodataValue ? QStringLiteral( "NODATA" ) : QString::number( *it ) ), QVariant::LongLong, QString(), -1, 0 ) ); } QgsFields fields = QgsProcessingUtils::combineFields( zones->fields(), newFields ); QString dest; std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields, zones->wkbType(), zones->sourceCrs() ) ); if ( !sink ) throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) ); it = zones->getFeatures( QgsFeatureRequest() ); while ( it.nextFeature( f ) ) { QgsAttributes attributes = f.attributes(); QHash< double, qgssize > fUniqueValues = featuresUniqueValues.value( f.id() ); for ( auto it = uniqueValues.constBegin(); it != uniqueValues.constEnd(); ++it ) { attributes += fUniqueValues.value( *it, 0 ); } QgsFeature outputFeature; outputFeature.setGeometry( f.geometry() ); outputFeature.setAttributes( attributes ); sink->addFeature( outputFeature, QgsFeatureSink::FastInsert ); } QVariantMap outputs; outputs.insert( QStringLiteral( "OUTPUT" ), dest ); return outputs; }