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[Jake Ostien <tostien@xxxxxxxxx>]

OK, nevermind...I figured out subsystems do work.

For example...

SubSystem x(0);
SusSystem y(1);

BoundaryCondition(zero,mesh,left,x);

applies the BC only for the x dof.

-Jake

Jake Ostien wrote:
> Hi,
>
> This seems like it should be easy, so I am sorry I have to ask. 
>
> How do I set a simple support (i.e. fixed dof in x, free dof in y) in a 
> 2D elasticity problem.  I have figured out how to do it if I am weakly 
> enforcing Dirichlet BC's in a DG formulation, but I can't figure out how 
> to do it for the classical formulation using BoundaryConditions.
>
> Here is what I have tried (among other things) using pieces of code from 
> the elasticity demo, but for 2D...
>
> ..
> ..
> ..
> Clamp c(mesh);
> Function cx = c[0];
> Left left;
> BoundaryCondition bcl(cx, mesh, left);
> ..
> ..
> ..
>
> But I get an error that says
>
> terminate called after throwing an instance of 'std::runtime_error'
>   what():  *** Error: Sub functions can only be extracted from discrete 
> functions.
> Aborted
>
>
> After nosing around a bit, its not clear if I need to create a SubSystem 
> or not, but I think I would run into the same problem as above.
> Any suggestions will be appreciated.
>
> -Jake
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