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;
}
