dolfin team mailing list archive

[Marie Rognes <meg@xxxxxxxxxxx>]

Hi,

I seem to have a problem with "manually" applying boundary 
conditions to the system of linear equations. In particular, 
I get the following error

   Traceback (most recent call last):
     File "testbc.py", line 38, in ?
       bc.apply(A, b, a)
     File

"/home/meg/src/dolfin/dolfin/local/lib/python2.4/site-packages/dolfin/dolfin.py",
   line 5742, in apply
       return _dolfin.DirichletBC_apply(*args)
   NotImplementedError: Wrong number of arguments for 
overloaded
   function 'DirichletBC_apply'.
     Possible C/C++ prototypes are:
       apply(dolfin::GenericMatrix &,dolfin::GenericVector
   &,dolfin::Form const &)
       apply(dolfin::GenericMatrix &,dolfin::GenericVector 
&,ufc::form
   const &)
       apply(dolfin::GenericMatrix &,dolfin::GenericVector
   &,dolfin::GenericVector const &,dolfin::Form const &)
       apply(dolfin::GenericMatrix &,dolfin::GenericVector
   &,dolfin::GenericVector const &,ufc::form const &)

with the following code

   from dolfin import *

   class Zero(Function):
       def __init__(self, element, mesh):
           Function.__init__(self, element, mesh)
       def eval(self, values, x):
           values[0] = 0.0

   class DirichletBoundary(SubDomain):
       def inside(self, x, on_boundary):
           return bool(on_boundary)

   def Mass(element, f):
       v = TestFunction(element)
       u = TrialFunction(element)
       a = v*u*dx
       L = v*f*dx
       return [a, L]

   # The element space
   element = FiniteElement("Lagrange", "triangle", 1)

   # The mesh, boundary and boundary conditions
   mesh = UnitSquare(2,2)
   boundary = DirichletBoundary()
   zero = Zero(element, mesh)
   bc = DirichletBC(zero, mesh, boundary)

   # Construct and assemble the forms
   [a, L] = Mass(element, zero)
   A = assemble(a, mesh)
   b = assemble(L, mesh)

   # Try applying boundary conditions:
   bc.apply(A, b, a)


Am I missing something obvious here?


In addition, if I try just using

   zero = Function(mesh, 0.0)

in the above, I get the following error from ffc. However, I 
guess that I could just have a look at that when I find some 
time myself...

   Traceback (most recent call last):
     File "testbc.py", line 33, in ?
       [a, L] = Mass(element, zero)
     File "testbc.py", line 18, in Mass
       L = v*f*dx
     File

"/home/meg/src/ffc/ffc_current/src/ffc/compiler/language/algebra.py",
   line 77, in __mul__
       return Form(self) * other
     File

"/home/meg/src/ffc/ffc_current/src/ffc/compiler/language/algebra.py",
   line 631, in __mul__
       w.monomials = [p*other for p in self.monomials]
     File

"/home/meg/src/ffc/ffc_current/src/ffc/compiler/language/algebra.py",
   line 446, in __mul__
       w1 = Monomial(other)
     File

"/home/meg/src/ffc/ffc_current/src/ffc/compiler/language/algebra.py",
   line 405, in __init__
       self.coefficients = [Coefficient(other, index)]
     File

"/home/meg/src/ffc/ffc_current/src/ffc/compiler/language/tokens.py",
   line 53, in __init__
       self.n0 = Index(function.n0)
     File

"/home/meg/src/dolfin/dolfin/local/lib/python2.4/site-packages/dolfin/dolfin.py",
   line 2733, in <lambda>
       __getattr__ = lambda self, name: _swig_getattr(self,
   cpp_Function, name)
     File

"/home/meg/src/dolfin/dolfin/local/lib/python2.4/site-packages/dolfin/dolfin.py",
   line 34, in _swig_getattr
       raise AttributeError,name
   AttributeError: n0



Thanks!

--
Marie E. Rognes
Ph.D Fellow,
Centre of Mathematics for Applications,
University of Oslo
http://folk.uio.no/meg