Index: trunk/Mars/mgeom/MGeom.h
===================================================================
--- trunk/Mars/mgeom/MGeom.h	(revision 9900)
+++ trunk/Mars/mgeom/MGeom.h	(revision 10089)
@@ -79,4 +79,5 @@
     Float_t GetY() const  { return fY; }
 
+    virtual Float_t GetL() const = 0;    // Length of a side to a neighbor
     virtual Float_t GetT() const = 0;    // Maximum elongation
 
Index: trunk/Mars/mgeom/MGeomPix.h
===================================================================
--- trunk/Mars/mgeom/MGeomPix.h	(revision 9900)
+++ trunk/Mars/mgeom/MGeomPix.h	(revision 10089)
@@ -53,5 +53,5 @@
     Float_t GetD() const  { return fD; }         // Distance between two parallel sides
     Float_t GetL() const  { return fD*gsTan30; } // Length of one of the parallel sides
-    Float_t GetT() const  { return fD/gsTan60; } // Distance between two opposite edges (traverse)
+    Float_t GetT() const  { return fD/gsTan60; } // Half distance between two opposite edges (traverse)
 
     Float_t GetDx() const { return fD; }         // Distance of two rows in x-direction (without rotation)
Index: trunk/Mars/mgeom/MGeomRectangle.cc
===================================================================
--- trunk/Mars/mgeom/MGeomRectangle.cc	(revision 9900)
+++ trunk/Mars/mgeom/MGeomRectangle.cc	(revision 10089)
@@ -97,9 +97,18 @@
 // ------------------------------------------------------------------------
 //
-// Return the distance of the two opposite edges.
+// Return the distance from the center to one of the two opposite edges.
 //
 Float_t MGeomRectangle::GetT() const
 {
     return TMath::Hypot(fW, fH)/2;
+}
+
+// ------------------------------------------------------------------------
+//
+// Return the average length of the sides
+//
+Float_t MGeomRectangle::GetL() const
+{
+    return (fW+fH)/2;
 }
 
Index: trunk/Mars/mgeom/MGeomRectangle.h
===================================================================
--- trunk/Mars/mgeom/MGeomRectangle.h	(revision 9900)
+++ trunk/Mars/mgeom/MGeomRectangle.h	(revision 10089)
@@ -31,4 +31,5 @@
     Float_t GetH() const { return fH; }
     Float_t GetT() const;
+    Float_t GetL() const;
 
     Bool_t  IsInside(Float_t px, Float_t py) const;