form_option_type (2rheolef)

This class is used to send options to the integrate function when building a form. It allows to set the quadrature formulae that is used for numerical integration see quadrature_option_type(2) and two boolean flags.

ignore_sys_coord

This flag has effects only for axisymmetric coordinate systems. When set, it omits the r weight in the r dr dz measure during the numerical integration performed the integrate function. This feature is usefull for computing the stream function in the axisymmetric case.

lump

This flag, when set, perfoms a mass lumping procedure on the matrix at the element level:

a(i,i) := sum(j) a(i,j)

The resulting matrix is diagonal. This feature is usefull for computing a diagonal approximation of the mass matrix for the continuous P1 element.

invert

This flag, when set, perfoms a local inversion on the matrix at the element level:

a := inv(a)

This procedure is allowed only when the global matrix is block diagonal, e.g. for discontinuous or bubble approximations. This property is true when basis functions have a compact support inside exactly one element.

All flags are set to false by default.

struct form_option_type : quadrature_option_type {
// allocators:
  form_option_type();
  form_option_type (const form_option_type& fopt);
  form_option_type (const quadrature_option_type& qopt);
  form_option_type& operator= (const form_option_type& fopt);
  operator quadrature_option_type() const { return *this; }
// data:
  bool ignore_sys_coord, lump, invert;
};

quadrature_option_type(2)