.\"
.de Id
..
.de Sp
.if n .sp
.if t .sp 0.4
..
.TH eye 2rheolef "rheolef-7.0" "rheolef-7.0" "rheolef-7.0"
.\" label: /*Class:eye
.SH NAME
\fBeye\fP - the identity matrix
.SH DESCRIPTION

Following \fBoctave\fP, the name \fBeye_rep\fP class is used in place of I to denote identity matrices
because I is often used as a subscript or as sqrt(-1). The dimensions of \fBeye_rep\fP are
determined by the context.
This class is here useful in the context of preconditioner interfaces: it allows
calls of algorithms without any preconditioners, e.g.
.\" begin_example
.Sp
.nf
    int status = cg (a, x, b, eye_rep<Float>(), 100, 1e-7);
.Sp
.fi
.\" end_example
.\" skip start:AUTHOR:

.\" skip start:DATE:

.\" END
.SH IMPLEMENTATION
.\" begin_example
.Sp
.nf
template<class T, class M = rheo_default_memory_model>
class eye_rep : public solver_abstract_rep<T,M> {
public:
  eye_rep (const solver_option& opt = solver_option());
  void update_values (const csr<T,M>&) {}
  vec<T,M> operator*   (const vec<T,M>& x) const { return x; }
  vec<T,M> solve       (const vec<T,M>& x) const { return x; }
  vec<T,M> trans_solve (const vec<T,M>& x) const { return x; }
};
.Sp
.fi
.\" end_example
.SH 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.