Adapted GeoXF to be able to handle scale transformations.

The parameterization of transformations is used within GeoSerialTransformer. It uses GeoXf, which has been modified in this version to accommodate scale transformations. Probably quite safe, but we should have our eye out in case we screw something up.

GeoModelCore/GeoModelKernel/src/GeoXF.cxx

@@ -231,23 +231,25 @@ __attribute__ ((flatten))
     //
     // Get the translation part and the rotation part:
     //
-    GeoTrf::RotationMatrix3D rotate = m_xf.rotation ();
+    Eigen::Matrix3d linear = m_xf.linear ();
+    Eigen::EigenSolver<GeoTrf::RotationMatrix3D> solver(linear);
+    Eigen::MatrixXcd D = solver.eigenvalues().asDiagonal();
+    Eigen::MatrixXcd V = solver.eigenvectors();
+        
     GeoTrf::Vector3D translate = m_xf.translation ();
-    Eigen::AngleAxis<double> aa(rotate);
-    //
-    // Evaluate the function
-    //
     double nTimes = (*m_function) (x);
     //
     // Modify:
     //
     translate *= nTimes;
-    double& delta = aa.angle();
-    delta *= nTimes;
+    Eigen::Matrix3cd DPowN=Eigen::Matrix3cd::Zero();
+    for (unsigned int i=0;i<3;i++) DPowN(i,i)=pow(D(i,i),nTimes);
     //
     // Now compose these and return a result:
     //
-    return GeoTrf::Translation3D (translate) * GeoTrf::Transform3D(aa);
+    GeoTrf::Transform3D tRPowN;
+    tRPowN.linear()=(V*DPowN*V.inverse()).real();
+    return GeoTrf::Translation3D (translate) * tRPowN;
   }
 
   GeoTrf::Transform3D Pow::operator        () (const GeoGenfun::Argument & argument) const