OpDomainTangentMatrix Struct Reference

Integrate the domain tangent matrix (LHS) More...

Inheritance diagram for OpDomainTangentMatrix:

Collaboration diagram for OpDomainTangentMatrix:

Public Member Functions
	OpDomainTangentMatrix (std::string row_field_name, std::string col_field_name, boost::shared_ptr< MatrixDouble > field_grad_mat)
MoFEMErrorCode	iNtegrate (EntData &row_data, EntData &col_data)

Private Attributes
boost::shared_ptr< MatrixDouble >	fieldGradMat

Detailed Description

Integrate the domain tangent matrix (LHS)

\[ \sum\limits_j {\left[ {\int\limits_{{\Omega _e}} {\left( {{a_n}\nabla {\phi _i} \cdot \nabla {\phi _j} - a_n^3\nabla {\phi _i}\left( {\nabla u \cdot \nabla {\phi _j}} \right)\nabla u} \right)d{\Omega _e}} } \right]\delta {U_j}} = \int\limits_{{\Omega _e}} {{\phi _i}fd{\Omega _e}} - \int\limits_{{\Omega _e}} {\nabla {\phi _i}{a_n}\nabla ud{\Omega _e}} \\ {a_n} = \frac{1}{{{{\left( {1 + {{\left| {\nabla u} \right|}^2}} \right)}^{\frac{1}{2}}}}} \]

Definition at line 40 of file minimal_surface_equation.cpp.

Constructor & Destructor Documentation

OpDomainTangentMatrix()

OpDomainTangentMatrix::OpDomainTangentMatrix ( std::string row_field_name, std::string col_field_name, boost::shared_ptr< MatrixDouble > field_grad_mat )

inline

Definition at line 42 of file minimal_surface_equation.cpp.

      : AssemblyDomainEleOp(row_field_name, col_field_name,
                            DomainEleOp::OPROWCOL),
        fieldGradMat(field_grad_mat) {}

Member Function Documentation

iNtegrate()

MoFEMErrorCode OpDomainTangentMatrix::iNtegrate ( EntData & row_data, EntData & col_data )

inline

Definition at line 48 of file minimal_surface_equation.cpp.

                                                                 {
    MoFEMFunctionBegin;
 
    auto &locLhs = AssemblyDomainEleOp::locMat;
 
    // get element area
    const double area = getMeasure();
 
    // get number of integration points
    const int nb_integration_points = getGaussPts().size2();
    // get integration weights
    auto t_w = getFTensor0IntegrationWeight();
    // get gradient of the field at integration points
    auto t_field_grad = getFTensor1FromMat<2>(*fieldGradMat);
 
    // get derivatives of base functions on row
    auto t_row_diff_base = row_data.getFTensor1DiffN<2>();
 
    // START THE LOOP OVER INTEGRATION POINTS TO CALCULATE LOCAL MATRIX
    for (int gg = 0; gg != nb_integration_points; gg++) {
 
      const double a = t_w * area;
      const double an = 1. / std::sqrt(1 + t_field_grad(i) * t_field_grad(i));
 
      for (int rr = 0; rr != AssemblyDomainEleOp::nbRows; ++rr) {
        // get derivatives of base functions on column
        auto t_col_diff_base = col_data.getFTensor1DiffN<2>(gg, 0);
 
        for (int cc = 0; cc != AssemblyDomainEleOp::nbRows; cc++) {
 
          // calculate components of the local matrix
          locLhs(rr, cc) += (t_row_diff_base(i) * t_col_diff_base(i)) * an * a -
                            t_row_diff_base(i) *
                                (t_field_grad(i) * t_col_diff_base(i)) *
                                t_field_grad(i) * an * an * an * a;
 
          // move to the derivatives of the next base functions on column
          ++t_col_diff_base;
        }
 
        // move to the derivatives of the next base functions on row
        ++t_row_diff_base;
      }
 
      // move to the weight of the next integration point
      ++t_w;
      // move to the gradient of the field at the next integration point
      ++t_field_grad;
    }
 
    MoFEMFunctionReturn(0);
  }

Member Data Documentation

fieldGradMat

boost::shared_ptr<MatrixDouble> OpDomainTangentMatrix::fieldGradMat

private

Definition at line 102 of file minimal_surface_equation.cpp.

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The documentation for this struct was generated from the following file:

• tutorials/scl-5/minimal_surface_equation.cpp