CPPLapack Code

//=============================================================================
/*! calculate determinant */
inline double det(const dsymat3& A)
{
  return
    +A(0,0)*A(1,1)*A(2,2) -A(0,0)*A(2,1)*A(2,1)
    +A(1,0)*A(2,1)*A(2,0) -A(1,0)*A(1,0)*A(2,2)
    +A(2,0)*A(1,0)*A(2,1) -A(2,0)*A(1,1)*A(2,0);
}

//=============================================================================
/*! calculate inverse */
inline dsymat3 inv(const dsymat3& A)
{
  const double Adet( det(A) );
  dsymat3 Ainv;
  Ainv(0,0) =(A(1,1)*A(2,2)-A(2,1)*A(2,1))/Adet;
  Ainv(1,0) =(A(2,1)*A(2,0)-A(1,0)*A(2,2))/Adet;
  Ainv(1,1) =(A(0,0)*A(2,2)-A(2,0)*A(2,0))/Adet;
  Ainv(2,0) =(A(1,0)*A(2,1)-A(1,1)*A(2,0))/Adet;
  Ainv(2,1) =(A(1,0)*A(2,0)-A(0,0)*A(2,1))/Adet;
  Ainv(2,2) =(A(0,0)*A(1,1)-A(1,0)*A(1,0))/Adet;
  return Ainv;
}

//=============================================================================
/*!  */
inline dsymat3 rotate(const dsymat3& m, const dquater& q)
{
  dgemat3 R(q2m(q));
  dgemat3 Rm(R*m);
  dsymat3 RmRT(0.);//not dgemat3
  for(long i=0; i<3; i++){
    for(long j=0; j<=i; j++){
      for(long k=0; k<3; k++){
        RmRT(i,j) +=Rm(i,k)*R(j,k);
      }
    }
  }
  return RmRT;
}