diff --git a/src/org/hwo/ui/JDiagram.java b/src/org/hwo/ui/JDiagram.java
index ee5e485..0824bbf 100644
--- a/src/org/hwo/ui/JDiagram.java
+++ b/src/org/hwo/ui/JDiagram.java
@@ -411,18 +411,23 @@ public class JDiagram extends JComponent implements PlotProviderListener, Bounde
 		
 		max = new Double[this.plotProvider.getMaxOrdinate()+1];
 		min = new Double[this.plotProvider.getMaxOrdinate()+1];
-				
-		for (int graph=0; graph < this.plotProvider.getNumGraphs(); graph++){
-			ordinate = this.plotProvider.getOrdinate(graph);
-			for (int n=0;n<this.plotProvider.getLength(); n++){				
-				Float value		= this.plotProvider.getValue(n, graph);
-				if (value != null)
-				{
-					if ((min[ordinate] == null) || (value < min[ordinate]))
-						min[ordinate] = value.doubleValue();
-					if ((max[ordinate] == null) || (value > max[ordinate]))
-						max[ordinate] = value.doubleValue();
-				};
+
+		for (int n=0;n<this.plotProvider.getLength(); n++){			
+			for (int graph=0; graph < this.plotProvider.getNumGraphs(); graph++){
+				double pos = this.plotProvider.getPosition(n,graph);
+
+				if ((pos >= abszissMinimum) && (pos < (abszissMinimum + abszissWindow))){				
+					ordinate = this.plotProvider.getOrdinate(graph);
+					
+					Float value		= this.plotProvider.getValue(n, graph);
+					if (value != null)
+					{
+						if ((min[ordinate] == null) || (value < min[ordinate]))
+							min[ordinate] = value.doubleValue();
+						if ((max[ordinate] == null) || (value > max[ordinate]))
+							max[ordinate] = value.doubleValue();
+					}
+				}
 			}
 		}