NAME

       integrate_option - send options to the integrate function

DESCRIPTION

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

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 useful for computing the stream function in
              the axisymmetric case.

       lump   This flag, when set, performs 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 useful for computing a diagonal
              approximation of the mass matrix for the continuous P1 element.

       invert This flag, when set, performs 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.

DEFAULT FLAG VALUES

       All flags are set to false by default.

IMPLEMENTATION

       struct integrate_option : quadrature_option {
       // allocators:
         integrate_option();
         integrate_option (const integrate_option& fopt);
         integrate_option (const quadrature_option& qopt);
         integrate_option& operator= (const integrate_option& fopt);
       // data:
         bool ignore_sys_coord, lump, invert;
       };

SEE ALSO

       quadrature_option(2)

COPYRIGHT

       Copyright (C) 2000-2018 Pierre Saramito <Pierre.Saramito@imag.fr> GPLv3+: GNU GPL  version
       3  or  later  <http://gnu.org/licenses/gpl.html>.   This is free software: you are free to
       change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.