Line data    Source code

       1             : // The libMesh Finite Element Library.
       2             : // Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner
       3             : 
       4             : // This library is free software; you can redistribute it and/or
       5             : // modify it under the terms of the GNU Lesser General Public
       6             : // License as published by the Free Software Foundation; either
       7             : // version 2.1 of the License, or (at your option) any later version.
       8             : 
       9             : // This library is distributed in the hope that it will be useful,
      10             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             : // Lesser General Public License for more details.
      13             : 
      14             : // You should have received a copy of the GNU Lesser General Public
      15             : // License along with this library; if not, write to the Free Software
      16             : // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      17             : 
      18             : 
      19             : 
      20             : #ifndef LIBMESH_QUADRATURE_JACOBI_H
      21             : #define LIBMESH_QUADRATURE_JACOBI_H
      22             : 
      23             : // Local includes
      24             : #include "libmesh/quadrature.h"
      25             : 
      26             : namespace libMesh
      27             : {
      28             : 
      29             : /**
      30             :  * This class implements two (for now) Jacobi-Gauss quadrature
      31             :  * rules.  These rules have the same order of accuracy as the
      32             :  * normal Gauss quadrature rules, but instead of integrating
      33             :  * a weight function w(x)=1, they integrate w(x)=(1-x)^alpha * (1+x)^beta.
      34             :  * The reason that they are useful is that they allow you to
      35             :  * implement conical product rules for triangles and tetrahedra.
      36             :  * Although these product rules are non-optimal (use more points
      37             :  * than necessary) they are automatically constructable for high
      38             :  * orders of accuracy where other formulae may not exist.
      39             :  *
      40             :  * There is not much sense in using this class directly,
      41             :  * since it only provides 1D rules, weighted, as described before.
      42             :  * Still, this class is particularly helpful: check \p QGauss
      43             :  * for triangles and tetrahedra, with orders beyond \p THIRTIETH.
      44             :  *
      45             :  * \author John W. Peterson
      46             :  * \date 2003
      47             :  * \brief Implements 1D Gauss-Jacobi quadrature rules of various orders.
      48             :  */
      49             : class QJacobi final : public QBase
      50             : {
      51             : public:
      52             : 
      53             :   /**
      54             :    * Constructor.  Currently, only one-dimensional rules provided.
      55             :    */
      56       26913 :   QJacobi (unsigned int dim,
      57             :            Order order=INVALID_ORDER,
      58             :            unsigned int a=1,
      59       26913 :            unsigned int b=0) :
      60             :     QBase(dim, order),
      61       24421 :     _alpha(a),
      62       26913 :     _beta(b)
      63             :   {
      64       26913 :     if (_dim == 1)
      65       26913 :       init(EDGE2);
      66       26913 :   }
      67             : 
      68             :   /**
      69             :    * Copy/move ctor, copy/move assignment operator, and destructor are
      70             :    * all explicitly defaulted for this simple class.
      71             :    */
      72           0 :   QJacobi (const QJacobi &) = default;
      73             :   QJacobi (QJacobi &&) = default;
      74             :   QJacobi & operator= (const QJacobi &) = default;
      75             :   QJacobi & operator= (QJacobi &&) = default;
      76       26464 :   virtual ~QJacobi() = default;
      77             : 
      78             :   /**
      79             :    * \returns The \p QuadratureType, either \p QJACOBI_1_0 or \p
      80             :    * QJACOBI_2_0.
      81             :    */
      82             :   virtual QuadratureType type() const override;
      83             : 
      84             :   virtual std::unique_ptr<QBase> clone() const override;
      85             : 
      86             : private:
      87             :   unsigned int _alpha;
      88             :   unsigned int _beta;
      89             : 
      90             :   virtual void init_1D () override;
      91             : };
      92             : 
      93             : } // namespace libMesh
      94             : 
      95             : #endif // LIBMESH_QUADRATURE_JACOBI_H