--- a/artifacts/src/main/java/org/dive4elements/river/exports/process/WDiffProcessor.java	Fri Mar 07 11:12:59 2014 +0100
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/process/WDiffProcessor.java	Fri Mar 07 11:15:38 2014 +0100
@@ -8,8 +8,16 @@
 
 package org.dive4elements.river.exports.process;
 
+import org.dive4elements.artifactdatabase.state.ArtifactAndFacet;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.river.artifacts.D4EArtifact;
+import org.dive4elements.river.artifacts.access.RiverAccess;
+import org.dive4elements.river.artifacts.context.RiverContext;
 import org.dive4elements.river.artifacts.model.FacetTypes;
+import org.dive4elements.river.artifacts.model.ZoomScale;
+import org.dive4elements.river.artifacts.resources.Resources;
 import org.dive4elements.river.exports.DiagramGenerator;
+import org.dive4elements.river.themes.ThemeDocument;
 
 public class WDiffProcessor extends WOutProcessor {
 
@@ -18,6 +26,34 @@
 
     public final static String I18N_WDIFF_YAXIS_LABEL_DEFAULT = "m";
 
+    public static final String I18N_SUBTITLE_RADIUS =
+        "chart.subtitle.radius";
+
+    @Override
+    public void doOut(
+            DiagramGenerator generator,
+            ArtifactAndFacet bundle,
+            ThemeDocument    theme,
+            boolean          visible) {
+        CallContext context = generator.getCallContext();
+        Double start = (Double)context.getContextValue("startkm");
+        Double end = (Double)context.getContextValue("endkm");
+        if (start != null && end != null) {
+            D4EArtifact artifact = (D4EArtifact)bundle.getArtifact();
+            RiverContext fc = (RiverContext)context.globalContext();
+            // Adaptive smoothing, based on zoom factor/diagram extents.
+            ZoomScale scales = (ZoomScale)fc.get("zoomscale");
+            RiverAccess access = new RiverAccess((D4EArtifact)artifact);
+            String river = access.getRiverName();
+
+            double radius = scales.getRadius(river, start, end);
+            generator.addSubtitle(Resources.getMsg(
+                context.getMeta(),
+                I18N_SUBTITLE_RADIUS,
+                new Object[] { radius }));
+        }
+        super.doOut(generator, bundle, theme, visible);
+    }
     @Override
     public boolean canHandle(String facetType) {
         if (facetType == null) {