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implement count function, implement Ignore NoData Parameter, move get…
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…CellValuesFromBlockStack() to QgsRasterAnalysisUtils
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@root676 @nyalldawson
root676 authored and nyalldawson committed Jul 2, 2020
1 parent d977db4 commit 56a590e
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Showing 4 changed files with 62 additions and 41 deletions.
73 changes: 34 additions & 39 deletions src/analysis/processing/qgsalgorithmcellstatistics.cpp
View file
Expand Up @@ -34,7 +34,7 @@ QString QgsCellStatisticsAlgorithm::name() const

QStringList QgsCellStatisticsAlgorithm::tags() const
{
return QObject::tr( "cell,pixel,statistic,mean,sum,majority,minority,variance,variety,range,median,minimum,maximum" ).split( ',' );
return QObject::tr( "cell,pixel,statistic,count,mean,sum,majority,minority,variance,variety,range,median,minimum,maximum" ).split( ',' );
}

QString QgsCellStatisticsAlgorithm::group() const
Expand All @@ -58,6 +58,7 @@ QString QgsCellStatisticsAlgorithm::shortHelpString() const
"raster cells per output raster cell location: "
"<ul> "
" <li>Sum</li>"
" <li>Count</li>"
" <li>Mean</li>"
" <li>Median</li>"
" <li>Standard deviation</li>"
Expand All @@ -71,7 +72,8 @@ QString QgsCellStatisticsAlgorithm::shortHelpString() const
"</ul> "
"Input raster layers that do not match the cell size of the reference raster layer will be "
"resampled using nearest neighbor resampling.\n"
"<i>Calculation details - general:</i> NoData values in any of the input layers will result in a NoData cell output.\n"
"<i>Calculation details - general:</i> NoData values in any of the input layers will result in a NoData cell output if the Ignore NoData parameter is not set.\n"
"<i>Calculation details - Count:</i> Count will always result in the number of cells without NoData values at the current cell location."
"<i>Calculation details - Median:</i> If the number of input layers is even, the median will be calculated as the "
"arithmetic mean of the two middle values of the ordered cell input values.\n"
"<i>Calculation details - Minority/Majority:</i> If no unique minority or majority could be found, the result is NoData, except all "
Expand All @@ -90,6 +92,7 @@ void QgsCellStatisticsAlgorithm::initAlgorithm( const QVariantMap & )

QStringList statistics = QStringList();
statistics << QStringLiteral( "Sum" )
<< QStringLiteral( "Count" )
<< QStringLiteral( "Mean" )
<< QStringLiteral( "Median" )
<< QStringLiteral( "Standard deviation" )
Expand All @@ -102,6 +105,7 @@ void QgsCellStatisticsAlgorithm::initAlgorithm( const QVariantMap & )
<< QStringLiteral( "Variety" );

addParameter( new QgsProcessingParameterEnum( QStringLiteral( "STATISTIC" ), QObject::tr( "Statistic" ), statistics, false, 0, false ) );
addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "IGNORE_NODATA" ), QObject::tr( "Ignore NoData values" ), true) );

addParameter( new QgsProcessingParameterRasterLayer( QStringLiteral( "REF_LAYER" ), QObject::tr( "Reference layer" ) ) );

Expand All @@ -120,6 +124,9 @@ bool QgsCellStatisticsAlgorithm::prepareAlgorithm( const QVariantMap &parameters
QgsRasterLayer *referenceLayer = parameterAsRasterLayer( parameters, QStringLiteral( "REF_LAYER" ), context );
if ( !referenceLayer )
throw QgsProcessingException( invalidRasterError( parameters, QStringLiteral( "REF_LAYER" ) ) );

mIgnoreNoData = parameterAsBool( parameters, QStringLiteral( "IGNORE_NODATA" ), context);

mCrs = referenceLayer->crs();
mRasterUnitsPerPixelX = referenceLayer->rasterUnitsPerPixelX();
mRasterUnitsPerPixelY = referenceLayer->rasterUnitsPerPixelY();
Expand Down Expand Up @@ -175,6 +182,7 @@ QVariantMap QgsCellStatisticsAlgorithm::processAlgorithm( const QVariantMap &par

provider->setNoDataValue( 1, mNoDataValue );
qgssize layerSize = static_cast< qgssize >( mLayerWidth ) * static_cast< qgssize >( mLayerHeight );
const int countOfInputs = mInputs.size();

int maxWidth = QgsRasterIterator::DEFAULT_MAXIMUM_TILE_WIDTH;
int maxHeight = QgsRasterIterator::DEFAULT_MAXIMUM_TILE_HEIGHT;
Expand Down Expand Up @@ -213,50 +221,58 @@ QVariantMap QgsCellStatisticsAlgorithm::processAlgorithm( const QVariantMap &par
{
double result = 0;
bool hasNoData = false;
std::vector<double> cellValues = getCellValues( inputBlocks, row, col, hasNoData );
std::vector<double> cellValues = QgsRasterAnalysisUtils::getCellValuesFromBlockStack( inputBlocks, row, col, hasNoData );
int cellValueStackSize = cellValues.size();

if ( hasNoData )
if ( hasNoData && !mIgnoreNoData )
{
//output cell will always be NoData if NoData occurs in cellValueStack
//output cell will always be NoData if NoData occurs in cellValueStack and NoData is not ignored
//this saves unnecessary iterations on the cellValueStack
outputBlock->setValue( row, col, mNoDataValue );
if( statisticMethodIdx == 1)
outputBlock->setValue( row, col, cellValueStackSize);
else
{
outputBlock->setValue( row, col, mNoDataValue );
}
}
else
else if ( !hasNoData || (hasNoData && mIgnoreNoData) )
{
switch ( statisticMethodIdx )
{
case 0: //sum
result = std::accumulate( cellValues.begin(), cellValues.end(), 0.0 );
break;
case 1: //mean
case 1: //count
result = cellValueStackSize;
break;
case 2: //mean
result = QgsRasterAnalysisUtils::meanFromCellValues( cellValues, cellValueStackSize );
break;
case 2: //median
case 3: //median
result = QgsRasterAnalysisUtils::medianFromCellValues( cellValues, cellValueStackSize );
break;
case 3: //stddev
case 4: //stddev
result = QgsRasterAnalysisUtils::stddevFromCellValues( cellValues, cellValueStackSize );
break;
case 4: //variance
case 5: //variance
result = QgsRasterAnalysisUtils::varianceFromCellValues( cellValues, cellValueStackSize );
break;
case 5: //min
case 6: //min
result = QgsRasterAnalysisUtils::minimumFromCellValues( cellValues );
break;
case 6: //max
case 7: //max
result = QgsRasterAnalysisUtils::maximumFromCellValues( cellValues );
break;
case 7: //minority
case 8: //minority
result = QgsRasterAnalysisUtils::minorityFromCellValues( cellValues, mNoDataValue, cellValueStackSize );
break;
case 8: //majority
case 9: //majority
result = QgsRasterAnalysisUtils::majorityFromCellValues( cellValues, mNoDataValue, cellValueStackSize );
break;
case 9: //range
case 10: //range
result = QgsRasterAnalysisUtils::rangeFromCellValues( cellValues );
break;
case 10: //variety
case 11: //variety
result = QgsRasterAnalysisUtils::varietyFromCellValues( cellValues );
break;
default:
Expand All @@ -281,28 +297,7 @@ QVariantMap QgsCellStatisticsAlgorithm::processAlgorithm( const QVariantMap &par
return outputs;
}

std::vector<double> QgsCellStatisticsAlgorithm::getCellValues( const std::vector< std::unique_ptr< QgsRasterBlock > > &inputBlocks, int &row, int &col, bool &hasNoData )
{
//get all values from inputBlocks
std::vector<double> cellValues;
for ( auto &block : inputBlocks )
{
double value = 0;
if ( !block || !block->isValid() )
{
hasNoData = true;
break;
}
else
{
value = block->valueAndNoData( row, col, hasNoData );
if ( hasNoData )
break;
cellValues.push_back( value );
}
}
return cellValues;
}


///@endcond

Expand Down
3 changes: 1 addition & 2 deletions src/analysis/processing/qgsalgorithmcellstatistics.h
View file
Expand Up @@ -51,9 +51,8 @@ class QgsCellStatisticsAlgorithm : public QgsProcessingAlgorithm
QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;

private:
std::vector<double> getCellValues( const std::vector< std::unique_ptr< QgsRasterBlock > > &inputBlocks, int &row, int &col, bool &hasNoData );

std::vector< QgsRasterAnalysisUtils::RasterLogicInput > mInputs;
bool mIgnoreNoData;
Qgis::DataType mDataType = Qgis::Float32;
double mNoDataValue = -9999;
int mLayerWidth;
Expand Down
22 changes: 22 additions & 0 deletions src/analysis/processing/qgsrasteranalysisutils.cpp
View file
Expand Up @@ -287,6 +287,28 @@ void QgsRasterAnalysisUtils::applyRasterLogicOperator( const std::vector< QgsRas
destinationRaster->setEditable( false );
}

std::vector<double> QgsRasterAnalysisUtils::getCellValuesFromBlockStack( const std::vector< std::unique_ptr< QgsRasterBlock > > &inputBlocks, int &row, int &col, bool &hasNoData )
{
//get all values from inputBlocks
std::vector<double> cellValues;
for ( auto &block : inputBlocks )
{
double value = 0;
if ( !block || !block->isValid() )
{
hasNoData = true;
break;
}
else
{
value = block->valueAndNoData( row, col, hasNoData );
if ( hasNoData )
break;
cellValues.push_back( value );
}
}
return cellValues;
}

double QgsRasterAnalysisUtils::meanFromCellValues( std::vector<double> cellValues, int stackSize )
{
Expand Down
5 changes: 5 additions & 0 deletions src/analysis/processing/qgsrasteranalysisutils.h
View file
Expand Up @@ -91,6 +91,11 @@ namespace QgsRasterAnalysisUtils
std::function<void( const std::vector< std::unique_ptr< QgsRasterBlock > > &, bool &, bool &, int, int, bool )> &applyLogicFunc,
qgssize &noDataCount, qgssize &trueCount, qgssize &falseCount );

/**
* Returns a vector of double values obtained from a stack of input QgsRasterBlocks
*/
std::vector<double> getCellValuesFromBlockStack( const std::vector< std::unique_ptr< QgsRasterBlock > > &inputBlocks, int &row, int &col, bool &hasNoData );

/**
* Returns the arithmetic mean from a vector of cell values
*/
Expand Down

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