Add getter for Psi into g_proximal interface

Author: tkoskela

cpp/sopt/g_proximal.h

@@ -25,6 +25,8 @@ template <class SCALAR> class GProximal {
   virtual t_Proximal proximal_function() const = 0;
   // Returns the norm of x
   virtual Real proximal_norm(t_Vector const &x) const = 0;
-  
+  // Transforms input image to a different basis.
+  // Return linear_transform_identity() if transform not necessary.
+  virtual const t_LinearTransform &Psi() const = 0;
 }; // class GProximal
 #endif

cpp/sopt/l1_g_proximal.h

@@ -59,6 +59,13 @@ class L1GProximal : public GProximal<SCALAR> {
 	   };
   }
 
+  //! \brief Analysis operator Ψ
+  //! \details Under-the-hood, the object is actually owned by the l1 proximal.
+  t_LinearTransform const &Psi() const override {
+    return l1_proximal().Psi();
+  }
+
+
 // All the public properties below are specific to the l1 proximal
 // and therefore not part of the interface
 
@@ -93,9 +100,6 @@ class L1GProximal : public GProximal<SCALAR> {
   SOPT_MACRO(weights, t_Vector);
 #undef SOPT_MACRO
 
-  //! \brief Analysis operator Ψ
-  //! \details Under-the-hood, the object is actually owned by the l1 proximal.
-  t_LinearTransform const &Psi() const { return l1_proximal().Psi(); }
   //! Analysis operator Ψ
   template <class... ARGS>
   typename std::enable_if<sizeof...(ARGS) >= 1, L1GProximal<SCALAR> &>::type Psi(