The program is :
from dolfin import *
import numpy as np
mesh = UnitSquareMesh(48,48)
P = VectorFunctionSpace( mesh,'DG',1 )
U = FunctionSpace(mesh,'DG',1)
W = P*U
( p,u ) = TrialFunctions(W)
( q,v ) = TestFunctions(W)
g = Expression('sin(pi/2*x[0])*sin(pi/2*x[1])',pi = np.pi )
f = Expression('(pi*pi/2.0+1)* sin(pi/2*x[0])*sin(pi/2*x[1])',pi=np.pi)
alpha = 1.1
n = FacetNormal(mesh)
h = CellSize(mesh)
a = dot(p,q)*dx - u*div(q)*dx -dot(p,grad(v))*dx \
+ avg(u)*jump(q,n)*dS \
- dot(jump(v,n) ,avg(grad(u)))*dS + alpha/h('+') *dot( jump(u,n),jump(v,n) )*dS \
- dot(v*n,grad(u))*ds + alpha/h*u*v*ds
L = f*v*dx - dot(g*n,q)*ds + alpha/h*g*v*ds
A = assemble(a)
b = assemble(L)
and there is a display on the screen :
Expecting expand_derivatives to have been applied.
what's wrong with it?
