BF_D_Q_Q1_2D.h

// ***********************************************************************
// Q1 element, discontinous, 2D, quadrilateral
// ***********************************************************************

// base function values
static void D_Q_Q1_2D_Funct(double xi, double eta, double *values)
{
  values[0] = 1.0;
  values[1] = xi;
  values[2] = eta;
  values[3] = xi*eta;
}

// values of the derivatives in xi direction
static void D_Q_Q1_2D_DeriveXi(double xi, double eta, double *values)
{
  values[0] = 0.0;
  values[1] = 1.0;
  values[2] = 0.0;
  values[3] = eta;
}

// values of the derivatives in eta direction
static void D_Q_Q1_2D_DeriveEta(double xi, double eta, double *values)
{
  values[0] = 0.0;
  values[1] = 0.0;
  values[2] = 1.0;
  values[3] = xi;
}

// values of the derivatives in xi-xi direction
static void D_Q_Q1_2D_DeriveXiXi(double xi, double eta, 
                                       double *values)
{
  values[0] = 0.0;
  values[1] = 0.0;
  values[2] = 0.0;
  values[3] = 0.0;
}

// values of the derivatives in xi-eta direction
static void D_Q_Q1_2D_DeriveXiEta(double xi, double eta, 
                                       double *values)
{
  values[0] = 0.0;
  values[1] = 0.0;
  values[2] = 0.0;
  values[3] = 1.0;
}

// values of the derivatives in eta-eta direction
static void D_Q_Q1_2D_DeriveEtaEta(double xi, double eta, 
                                       double *values)
{
  values[0] = 0.0;
  values[1] = 0.0;
  values[2] = 0.0;
  values[3] = 0.0;
}

// ***********************************************************************

TBaseFunct2D *BF_D_Q_Q1_2D_Obj = new TBaseFunct2D
        (4, BF_D_Q_Q1_2D, BFUnitSquare, 
         D_Q_Q1_2D_Funct, D_Q_Q1_2D_DeriveXi,
         D_Q_Q1_2D_DeriveEta, D_Q_Q1_2D_DeriveXiXi,
         D_Q_Q1_2D_DeriveXiEta, D_Q_Q1_2D_DeriveEtaEta, 1, 1,
         0, NULL);