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[Patrick Riesen <priesen@xxxxxxxxxxxxxxx>]

hello,

i'm under way of creating in-/outflow bc conditions by transferring a 
discrete 1D flow profile function onto a boundary subdomain of a 2D 
mesh. I marked the subdomain by a meshfunction and use an expression in 
which i evaluate the bcs values by extracting them from the 1D discrete 
solution as

BCInFlowProfile::eval (Array<double>& values, const Array<double>& x) const
{
 [....]
 velocity1Dprofile.eval(values, x_eval);
 [....]

}
i want to use "pointwise" method for applying the bcs, so that the 
velocities evaluated and specified on the vertices, but i get

dolfin/fem/DirichletBC.cpp:635: void 
dolfin::DirichletBC::compute_bc_pointwise(std::map<unsigned int, double, 
std::less<unsigned int>, std::allocator<std::pair<const unsigned int, 
double> > >&, dolfin::BoundaryCondition::LocalData&) const: Assertion 
`user_sub_domain' failed.


is using DirichletBC "pointwise" with a meshfunction and a subdomain id 
not possible?

regards,
patrick