Add Quantile based color map creation mode

Author: pierstitus

src/gui/raster/qgsrasterminmaxwidget.cpp

@@ -65,10 +65,9 @@ void QgsRasterMinMaxWidget::on_mLoadPushButton_clicked()
     double myMin = std::numeric_limits<double>::quiet_NaN();
     double myMax = std::numeric_limits<double>::quiet_NaN();
 
-    QgsRectangle myExtent; // empty == full
+    QgsRectangle myExtent = extent(); // empty == full
     if ( mCurrentExtentRadioButton->isChecked() )
     {
-      myExtent = mExtent; // current
       origin |= QgsRasterRenderer::MinMaxSubExtent;
     }
     else
@@ -77,10 +76,9 @@ void QgsRasterMinMaxWidget::on_mLoadPushButton_clicked()
     }
     QgsDebugMsg( QString( "myExtent.isEmpty() = %1" ).arg( myExtent.isEmpty() ) );
 
-    int mySampleSize = 0; // 0 == exact
+    int mySampleSize = sampleSize(); // 0 == exact
     if ( mEstimateRadioButton->isChecked() )
     {
-      mySampleSize = 250000;
       origin |= QgsRasterRenderer::MinMaxEstimated;
     }
     else

src/gui/raster/qgsrasterminmaxwidget.h

@@ -33,6 +33,9 @@ class GUI_EXPORT QgsRasterMinMaxWidget: public QWidget, private Ui::QgsRasterMin
 
     void setBands( const QList<int> & theBands ) { mBands = theBands; }
 
+    QgsRectangle extent() { QgsRectangle myExtent; return mCurrentExtentRadioButton->isChecked() ? mExtent : myExtent; }
+    int sampleSize() { return mEstimateRadioButton->isChecked() ? 250000 : 0; }
+
     // Load programmaticaly with current values
     void load() { on_mLoadPushButton_clicked(); }
 

src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp

@@ -103,7 +103,7 @@ QgsSingleBandPseudoColorRendererWidget::QgsSingleBandPseudoColorRendererWidget(
   mColorInterpolationComboBox->setCurrentIndex( 1 );
   mClassificationModeComboBox->addItem( tr( "Continuous" ), Continuous );
   mClassificationModeComboBox->addItem( tr( "Equal interval" ), EqualInterval );
-  //quantile would be nice as well
+  mClassificationModeComboBox->addItem( tr( "Quantile" ), Quantile );
 
   mNumberOfEntriesSpinBox->setValue( 5 ); // some default
 
@@ -343,6 +343,38 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
       }
     }
   }
+  else if ( mClassificationModeComboBox->itemData( mClassificationModeComboBox->currentIndex() ).toInt() == Quantile )
+  { // Quantile
+    mMinMaxWidget->load();
+
+    numberOfEntries = mNumberOfEntriesSpinBox->value();
+
+    int bandNr = mBandComboBox->itemData( bandComboIndex ).toInt();
+    //QgsRasterHistogram myRasterHistogram = mRasterLayer->dataProvider()->histogram( bandNr );
+
+    double myMin = std::numeric_limits<double>::quiet_NaN();
+    double myMax = std::numeric_limits<double>::quiet_NaN();
+
+    QgsRectangle myExtent = mMinMaxWidget->extent();
+    int mySampleSize = mMinMaxWidget->sampleSize();
+
+    double intervalDiff;
+    if ( numberOfEntries > 1 )
+    {
+      intervalDiff = 1.0 / ( numberOfEntries - 1 );
+      entryValues.reserve( numberOfEntries );
+      for ( int i = 0; i < numberOfEntries; ++i )
+      {
+        mRasterLayer->dataProvider()->cumulativeCut( bandNr, 0.0, i * intervalDiff, myMin, myMax, myExtent, mySampleSize );
+        entryValues.push_back( myMax );
+      }
+    }
+    else if ( numberOfEntries == 1 )
+    {
+      mRasterLayer->dataProvider()->cumulativeCut( bandNr, 0.0, 0.5, myMin, myMax, myExtent, mySampleSize );
+      entryValues.push_back( myMax );
+    }
+  }
   else // EqualInterval
   {
     numberOfEntries = mNumberOfEntriesSpinBox->value();
@@ -438,7 +470,7 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
 
 void QgsSingleBandPseudoColorRendererWidget::on_mClassificationModeComboBox_currentIndexChanged( int index )
 {
-  mNumberOfEntriesSpinBox->setEnabled( mClassificationModeComboBox->itemData( index ).toInt() == EqualInterval );
+  mNumberOfEntriesSpinBox->setEnabled( mClassificationModeComboBox->itemData( index ).toInt() != Continuous );
 }
 
 void QgsSingleBandPseudoColorRendererWidget::on_mColorRampComboBox_currentIndexChanged( int index )

src/gui/raster/qgssinglebandpseudocolorrendererwidget.h

@@ -31,7 +31,8 @@ class GUI_EXPORT QgsSingleBandPseudoColorRendererWidget: public QgsRasterRendere
     enum Mode
     {
       Continuous = 1, // Using breaks from color palette
-      EqualInterval = 2
+      EqualInterval = 2,
+      Quantile = 3
     };
 
     QgsSingleBandPseudoColorRendererWidget( QgsRasterLayer* layer, const QgsRectangle &extent = QgsRectangle() );