Import Geant4 11.4.0 source tree

source/geometry/magneticfield/include/G4ExactHelixStepper.hh

@@ -35,7 +35,7 @@
 //
 // As the field is assumed constant, an error is not calculated.
 
-// Author: J.Apostolakis, 28.01.2005.
+// Author: John Apostolakis (CERN), 28.01.2005.
 //         Implementation adapted from ExplicitEuler by W.Wander 
 // --------------------------------------------------------------------
 #ifndef G4EXACTHELIXSTEPPER_HH
@@ -48,40 +48,81 @@
 #include "G4MagHelicalStepper.hh"
 #include "G4Mag_EqRhs.hh"
 
+/**
+ * @brief G4ExactHelixStepper is a concrete class for particle motion in
+ * constant magnetic field. Helix a-la-Explicity Euler: x_1 = x_0 + helix(h)
+ * with helix(h) being a helix piece of length h.
+ * As the field is assumed constant, an error is not calculated.
+ */
+
 class G4ExactHelixStepper : public G4MagHelicalStepper
 {
   public:
 
+    /**
+     * Constructor for G4ExactHelixStepper.
+     *  @param[in] EqRhs Pointer to the standard equation of motion.
+     */
     G4ExactHelixStepper(G4Mag_EqRhs* EqRhs);
-   ~G4ExactHelixStepper() override;
+
+    /**
+     * Default Destructor.
+     */
+    ~G4ExactHelixStepper() override = default;
   
+    /**
+     * Copy constructor and assignment operator not allowed.
+     */
     G4ExactHelixStepper(const G4ExactHelixStepper&) = delete;
     G4ExactHelixStepper& operator=(const G4ExactHelixStepper&) = delete;
 
+    /**
+     * The stepper for the Runge Kutta integration.
+     * The stepsize is fixed, with the step size given by 'h'.
+     * Provides helix starting values y[0 to 6].
+     * Outputs yout[] and ZERO estimated error yerr[]=0.
+     *  @param[in] yInput Starting values array of integration variables.
+     *  @param[in] dydx Derivatives array.
+     *  @param[in] h The given step size.
+     *  @param[out] yout Integration output.
+     *  @param[out] yerr The estimated error.
+     */
     void Stepper( const G4double y[],
                   const G4double dydx[],
                         G4double h,
                         G4double yout[],
-                        G4double yerr[]  ) override;
-      // Step 'integration' for step size 'h'
-      // Provides helix starting at y[0 to 6]
-      // Outputs yout[] and ZERO estimated error yerr[]=0.
+                        G4double yerr[] ) override;
   
+    /**
+     * Same as Stepper() function above, but should perform a 'dump' step
+     * without error calculation. Assuming a constant field, the solution is
+     * a helix. Should NOT be called; issues a fatal exception as the Stepper
+     * must do all the work.
+     */
     void DumbStepper( const G4double y[],
                             G4ThreeVector Bfld,
                             G4double h,
                             G4double yout[] ) override;
-      // Performs a 'dump' Step without error calculation.
   
+    /**
+     * Estimates the maximum distance of curved solution and chord.
+     */
     G4double DistChord() const override;
-      // Estimate maximum distance of curved solution and chord ... 
 
-    G4int IntegratorOrder() const override;
+    /**
+     * Returns the order, 1, of integration.
+     */
+    inline G4int IntegratorOrder() const override { return 1; }
+
+    /**
+     * Returns the stepper type-ID, "kExactHelixStepper".
+     */
+    inline G4StepperType StepperType() const override { return kExactHelixStepper; }
 
   private:
 
+    /** Initial value of field at last step. */
     G4ThreeVector fBfieldValue;
-      // Initial value of field at last step
 };
 
 #endif