qgszonalstatistics.h

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/***************************************************************************
                          qgszonalstatistics.h  -  description
                          ----------------------------
    begin                : August 29th, 2009
    copyright            : (C) 2009 by Marco Hugentobler
    email                : marco at hugis dot net
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSZONALSTATISTICS_H
#define QGSZONALSTATISTICS_H
 
#include <cfloat>
#include <limits>
#include <map>
 
#include "qgis_analysis.h"
#include "qgscoordinatereferencesystem.h"
#include "qgsfeedback.h"
#include "qgsfields.h"
 
#include <QMap>
#include <QString>
 
class QgsGeometry;
class QgsVectorLayer;
class QgsRasterLayer;
class QgsRasterInterface;
class QgsRasterDataProvider;
class QgsRectangle;
class QgsField;
class QgsFeatureSink;
class QgsFeatureSource;

class ANALYSIS_EXPORT QgsZonalStatistics
{
  public:
    QgsZonalStatistics(
      QgsVectorLayer *polygonLayer, QgsRasterLayer *rasterLayer, const QString &attributePrefix = QString(), int rasterBand = 1, Qgis::ZonalStatistics stats = Qgis::ZonalStatistic::Default
    );

    QgsZonalStatistics(
      QgsVectorLayer *polygonLayer,
      QgsRasterInterface *rasterInterface,
      const QgsCoordinateReferenceSystem &rasterCrs,
      double rasterUnitsPerPixelX,
      double rasterUnitsPerPixelY,
      const QString &attributePrefix = QString(),
      int rasterBand = 1,
      Qgis::ZonalStatistics stats = Qgis::ZonalStatistic::Default
    );
 

    Qgis::ZonalStatisticResult calculateStatistics( QgsFeedback *feedback );

    static QString displayName( Qgis::ZonalStatistic statistic );

    static QString shortName( Qgis::ZonalStatistic statistic );

#ifndef SIP_RUN
    static QMap<Qgis::ZonalStatistic, QVariant> calculateStatistics(
      QgsRasterInterface *rasterInterface, const QgsGeometry &geometry, double cellSizeX, double cellSizeY, int rasterBand, Qgis::ZonalStatistics statistics
    );
#endif

    // Required to fix https://github.com/qgis/QGIS/issues/43245 (SIP is failing to convert the enum to values)

    static QMap<int, QVariant> calculateStatisticsInt(
      QgsRasterInterface *rasterInterface, const QgsGeometry &geometry, double cellSizeX, double cellSizeY, int rasterBand, Qgis::ZonalStatistics statistics
    ) SIP_PYNAME( calculateStatistics );
 
  private:
    QgsZonalStatistics() = default;
 
#ifndef SIP_RUN
    class FeatureStats
    {
      public:
        FeatureStats( bool storeValues = false, bool storeValueCounts = false )
          : mStoreValues( storeValues )
          , mStoreValueCounts( storeValueCounts )
        {}
 
        void reset()
        {
          sum = 0;
          count = 0;
          max = std::numeric_limits<double>::lowest();
          min = std::numeric_limits<double>::max();
          valueCount.clear();
          values.clear();
        }
 
        void addValue( double value, const QgsPointXY &point, double weight = 1.0 )
        {
          if ( !std::isnan( value ) )
          {
            if ( weight < 1.0 )
            {
              sum += value * weight;
              count += weight;
            }
            else
            {
              sum += value;
              ++count;
            }
            if ( value < min )
            {
              min = value;
              minPoint = point;
            }
            if ( value > max )
            {
              max = value;
              maxPoint = point;
            }
          }
          else
          {
            ++count;
          }
          if ( mStoreValueCounts )
            ++valueCount[value];
          if ( mStoreValues )
            values.append( value );
        }
        double sum = 0.0;
        double count = 0.0;
        double max = std::numeric_limits<double>::lowest();
        double min = std::numeric_limits<double>::max();
        QgsPointXY minPoint;
        QgsPointXY maxPoint;
        struct CompareNaNAware
        {
            bool operator()( double lhs, double rhs ) const { return ( std::isnan( lhs ) && !std::isnan( rhs ) ) || lhs < rhs; }
        };
        std::map<double, int64_t, CompareNaNAware> valueCount;
        QList<double> values;
 
      private:
        bool mStoreValues = false;
        bool mStoreValueCounts = false;
    };
 
    QString getUniqueFieldName( const QString &fieldName, const QList<QgsField> &newFields );
 
    QgsRasterInterface *mRasterInterface = nullptr;
    QgsCoordinateReferenceSystem mRasterCrs;
 
    double mCellSizeX = 0;
    double mCellSizeY = 0;

    int mRasterBand = 0;
    QgsVectorLayer *mPolygonLayer = nullptr;
    QString mAttributePrefix;
    Qgis::ZonalStatistics mStatistics = Qgis::ZonalStatistic::All;
#endif
};
 
// clazy:excludeall=qstring-allocations
 
#endif // QGSZONALSTATISTICS_H