Boundary conditions are now in place. Take a look and see if you like
it. If so, we can rename NewBoundaryCondition --> BoundaryCondition
and remove BoundaryValue (no longer needed).
The interface look as follows:
// Define a function (the values of the boundary condition)
class DirichletBC : public Function
{
real eval(const real* x)
{
return sin(x[0])*cos(x[1]);
}
};
DirichletBC g;
// Define a sub domain (where to put the boundary condition)
class DirichletBoundary : public SubDomain
{
bool inside(const real* x, bool on_boundary)
{
return x[0] < DOLFIN_EPS && on_boundary;
}
};
DirichleBoundary G;
// Define the boundary condition (function + sub domain)
NewBoundaryCondition bc(g, mesh, G);
// Apply boundary condition to linear system
bc.apply(A, b, form);
Note that I have also added an alternative interface for user-defined
functions that are scalar. The function above just returns the value.
The standard interface is
void eval(real* values, const real* x)
{
values[0] = ...
values[1] = ...
...
}
but for scalar functions, one can just return the value (or choose to
use the non-scalar version and set values[0]).
Also note that the boundary markers can still be defined by
MeshFunction over the facets, and a MeshFunction can also be read from
file. So one can have an XML mesh file and an XML mesh function file
that together define a mesh and its sub domains.
/Anders
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