NAME

interpolate - function or expression interpolation (rheolef-7.2)

DESCRIPTION

The interpolation function implements the usual Lagrange interpolation of a function or a class-function on a finite element space(2).

SYNOPSIS

    template <class Expression>


    field interpolate (const space& Xh, const Expression& expr);

Example The following code compute the Lagrange interpolation pi_h_u the function u(x):

   Float u(const point& x) { return exp(x[0]*x[1]); }


   ...


   geo omega('square');


   space Xh (omega, 'P1');


   field pi_h_u = interpolate (Xh, u);

EXPRESSIONS

It is possible to interpolate an expression involving a combination of functions, class-functions and fields:

    field vh = interpolate (Xh, sqrt(uh) + 2*max(0.,uh));

REINTERPOLATION

The reinterpolation of a field on another mesh or on another finite element space is also possible:

    geo omega2 ('square2');


    space X2h (omega2, 'P1');


    field uh2 = interpolate (X2h, pi_h_u);

Such a reinterpolation is very frequent in mesh adaptive loops.

IMPLEMENTATION

This documentation has been generated from file main/lib/interpolate.h

The implementation of expressions bases on the expression template and SFINAE C++ idioms.

AUTHOR

Pierre Saramito <Pierre.Saramito@imag.fr>

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.