.\"
.de Id
..
.de Sp
.if n .sp
.if t .sp 0.4
..
.TH form_option_type 2rheolef "rheolef-6.7" "rheolef-6.7" "rheolef-6.7"
.\" label: /*Class:doc
.SH NAME
\fBform_option_type\fP - send options to the integrate function
.\" skip: @findex integrate
.SH DESCRIPTION

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.
.SH FLAGS

.\" begin table
.\" start item
.TP
.B ignore_sys_coord
.\" skip:   @cindex axisymmetric geometry
This flag has effects only for axisymmetric coordinate systems.
When set, it omits the \fBr\fP weight in the \fBr dr dz\fP measure
during the numerical integration performed the \fBintegrate\fP function.
This feature is usefull for computing the stream function
in the axisymmetric case.
.\" start item
.TP
.B lump
.\" skip:   @cindex mass lumping
This flag, when set, perfoms a \fImass lumping procedure\fP
on the matrix at the element level:
.\" begin_example
.Sp
.nf
a(i,i) := sum(j) a(i,j)
.Sp
.fi
.\" end_example
The resulting matrix is diagonal.
This feature is usefull for computing a diagonal approximation
of the mass matrix for the continuous \fBP1\fP element.
.\" start item
.TP
.B invert
.\" skip:   @cindex local matrix inversion
This flag, when set, perfoms a \fIlocal inversion\fP
on the matrix at the element level:
.\" begin_example
.Sp
.nf
a := inv(a)
.Sp
.fi
.\" end_example
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.
.\" end table
.SH DEFAULT FLAG VALUES

All flags are set to false by default.
.\" END
.SH IMPLEMENTATION
.\" begin_example
.Sp
.nf
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);
#ifdef TO_CLEAN
  operator quadrature_option_type() const { return *this; }
#endif // TO_CLEAN
// data:
  bool ignore_sys_coord, lump, invert;
};
.Sp
.fi
.\" end_example

.\" LENGTH = 1
.SH SEE ALSO
quadrature_option_type(2)