Re: [Libmesh-users] writing/reading solutions of a transient model into files

[Kyunghoon L. <aer...@gm...>]

On Fri, Feb 8, 2013 at 10:17 AM, Jens Lohne Eftang <jle...@gm...>wrote:

> > I need to writing transient solutions into files and read them back later
> > (not for plotting).  It seems I can access transient solutions at each
> time
> > step by current_local_solution, which is NumericVector type.  I wonder if
> > there are some functions that deal with reading/writing NumericVector.
> >
> > K. Lee.
> Hi K.
>
> One way that's convenient is to add all the vectors that you wish to
> write out to a System using System::add_vector(), and then write out the
> EquationsSystems::write() with the WRITE_ADDITIONAL_DATA flag.
>
> Then you can just read them back into another System later ...
>
> Jens
>

Thanks for the tip, Jens.  I managed to writing/reading as follows:

In the lift system:

    lift_system.solve();

    // save the solution into a file
    lift_system.add_vector("lift_function");
    lift_system.get_vector("lift_function") = *(lift_system.solution);
    equation_systems.write("lift_data.dat", WRITE,
EquationSystems::WRITE_DATA | EquationSystems::WRITE_ADDITIONAL_DATA);

In the RB system:

    equation_systems.init ();

    // read lift function
    equation_systems.read("../lift_model/lift_data.dat", READ,
EquationSystems::READ_DATA | EquationSystems::READ_ADDITIONAL_DATA);

I found the caveat here is we need to make sure both systems have the same
system names.