diff --git a/chartfx-chart/src/main/java/de/gsi/chart/renderer/datareduction/DefaultDataReducer.java b/chartfx-chart/src/main/java/de/gsi/chart/renderer/datareduction/DefaultDataReducer.java
index d8d975907..748878c7b 100644
--- a/chartfx-chart/src/main/java/de/gsi/chart/renderer/datareduction/DefaultDataReducer.java
+++ b/chartfx-chart/src/main/java/de/gsi/chart/renderer/datareduction/DefaultDataReducer.java
@@ -2,11 +2,12 @@
 
 import java.security.InvalidParameterException;
 
+import javafx.beans.property.IntegerProperty;
+import javafx.beans.property.SimpleIntegerProperty;
+
 import de.gsi.chart.renderer.RendererDataReducer;
 import de.gsi.dataset.utils.AssertUtils;
 import de.gsi.dataset.utils.ProcessingProfiler;
-import javafx.beans.property.IntegerProperty;
-import javafx.beans.property.SimpleIntegerProperty;
 
 /**
  * Default data reduction algorithm implementation for the ErrorDataSet Renderer <br>
@@ -17,7 +18,6 @@
  * @author rstein
  */
 public class DefaultDataReducer implements RendererDataReducer {
-
     protected IntegerProperty minPointPixelDistance = new SimpleIntegerProperty(this, "minPixelDistance", 6) {
         @Override
         public void set(final int value) {
@@ -218,8 +218,8 @@ private int reducePointsInternal(final double[] xValues, final double[] yValues,
         yValues[count] = yValues[indexMax - 1];
         xPointErrorsNeg[count] = xPointErrorsPos[indexMax - 1];
         xPointErrorsPos[count] = xPointErrorsNeg[indexMax - 1];
-        yPointErrorsNeg[count] = yPointErrorsPos[indexMax - 1];
-        yPointErrorsPos[count] = yPointErrorsNeg[indexMax - 1];
+        yPointErrorsNeg[count] = yPointErrorsNeg[indexMax - 1];
+        yPointErrorsPos[count] = yPointErrorsPos[indexMax - 1];
         pointSelected[count] = pointSelected[indexMax - 1];
         styles[count] = styles[indexMax - 1];
         count++;
@@ -480,5 +480,4 @@ private int reducePointsInternal(final double[] xValues, final double[] yValues,
     public final void setMinPointPixelDistance(final int minPixelDistance) {
         minPointPixelDistanceProperty().setValue(minPixelDistance);
     }
-
 }
diff --git a/chartfx-chart/src/main/java/de/gsi/chart/renderer/spi/ErrorDataSetRenderer.java b/chartfx-chart/src/main/java/de/gsi/chart/renderer/spi/ErrorDataSetRenderer.java
index 22e97a8b9..7a96cfc42 100644
--- a/chartfx-chart/src/main/java/de/gsi/chart/renderer/spi/ErrorDataSetRenderer.java
+++ b/chartfx-chart/src/main/java/de/gsi/chart/renderer/spi/ErrorDataSetRenderer.java
@@ -1,12 +1,7 @@
 package de.gsi.chart.renderer.spi;
 
 import java.security.InvalidParameterException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Optional;
+import java.util.*;
 
 import javafx.collections.ObservableList;
 import javafx.geometry.Orientation;
@@ -493,12 +488,6 @@ protected void drawErrorSurface(final GraphicsContext gc, final CachedDataPoints
             xValuesSurface[xend - i] = localCachedPoints.xValues[i];
             yValuesSurface[xend - i] = localCachedPoints.errorYPos[i];
         }
-        // swap y coordinates at mid-point
-        if (nDataCount > 4) {
-            final double yTmp = yValuesSurface[nDataCount - 1];
-            yValuesSurface[nDataCount - 1] = yValuesSurface[xend - nDataCount + 1];
-            yValuesSurface[xend - nDataCount + 1] = yTmp;
-        }
 
         gc.setFillRule(FillRule.EVEN_ODD);
         gc.fillPolygon(xValuesSurface, yValuesSurface, nPolygoneEdges);
diff --git a/chartfx-samples/src/main/java/de/gsi/chart/samples/ErrorDataSetRendererStylingSample.java b/chartfx-samples/src/main/java/de/gsi/chart/samples/ErrorDataSetRendererStylingSample.java
index 7ca02dfc0..332bbc74e 100644
--- a/chartfx-samples/src/main/java/de/gsi/chart/samples/ErrorDataSetRendererStylingSample.java
+++ b/chartfx-samples/src/main/java/de/gsi/chart/samples/ErrorDataSetRendererStylingSample.java
@@ -360,6 +360,12 @@ private ParameterTab getRendererTab(final XYChart chart, final ErrorDataSetRende
         assumeSorted.selectedProperty().addListener((ch, old, selected) -> chart.requestLayout());
         pane.addToParameterPane("Assume sorted data: ", assumeSorted);
 
+        pane.addToParameterPane(" ", null);
+        final CheckBox cacheParallel = new CheckBox();
+        cacheParallel.selectedProperty().bindBidirectional(errorRenderer.parallelImplementationProperty());
+        cacheParallel.selectedProperty().addListener((ch, old, selected) -> chart.requestLayout());
+        pane.addToParameterPane("   Point cache parallel: ", cacheParallel);
+
         return pane;
     }