I've had this problem running scripts with ipython before. Try typing %reset and/or %clear out before %run to clear out variables.
Does the same thing happen on the command line? Jack On 12 April 2011 09:54, Ole Elvetun <question152...@answers.launchpad.net> wrote: > New question #152507 on DOLFIN: > https://answers.launchpad.net/dolfin/+question/152507 > > I'm working on a second-order elliptic equation, but I have some strange > effects regarding my solution, so I went back to the demo on solution of > poisson's equation with neumann bc, and the integral over the domain equal to > zero for uniqueness property. > > This demo works fine of course, but when I incorporate some SubDomains, and > split the unitcircle in three different domains, there is trouble. Just to > control that I have done it right, I do use all the same coefficients in all > subdomains, and when I do solve this modified version, I get the same > solution. But, if I call the same code several times, without actually > leaving python for each call, I get different results each time. > > My guess is that some information, which affects the solver, gets stored from > one call to the next. Does anyone have any thoughts on what might be wrong? > > Here is the code: > > from dolfin import * > > # Create mesh and define function space > mesh = UnitCircle(50) > V = FunctionSpace(mesh, "CG", 1) > R = FunctionSpace(mesh, "R", 0) > W = V * R > > #Separate the mesh into different regions using the SubDomain class > class dom1(SubDomain): > def inside(self, x, on_boundary): > return True if x[0]*x[0]+x[1]*x[1] <= 0.2*0.2 \ > else False > > class dom2(SubDomain): > def inside(self, x, on_boundary): > return True if (x[0]*x[0]+x[1]*x[1] >= 0.2*0.2 and \ > x[0]*x[0]+x[1]*x[1] <= 0.4*0.4) else False > > class dom3(SubDomain): > def inside(self, x, on_boundary): > return True if x[0]*x[0]+x[1]*x[1] >= 0.4*0.4 \ > else False > #Use the MeshFunction to assign a number to each cell, > #telling them which part of the domain they're in > subdomains = MeshFunction('uint', mesh, 2) > # Mark subdomains with numbers 0, 1 and 2 > subdomain0 = dom1() > subdomain0.mark(subdomains, 0) > subdomain1 = dom2() > subdomain1.mark(subdomains, 1) > subdomain2 = dom3() > subdomain2.mark(subdomains, 2) > > A1 = as_matrix ([[1.0, 0.0], [0.0, 1.0]]) > > # Define variational problem > (v, d) = TestFunctions(W) > (u, c) = TrialFunction(W) > f = Expression("10*exp(-(pow(x[0] - 0.5, 2) + pow(x[1] - 0.5, 2)) / 0.02)") > g = Expression("-sin(5*x[0])") > a = (inner(grad(v), A1*grad(u)) + v*c + d*u)*dx(0) + \ > (inner(grad(v), A1*grad(u)) + v*c + d*u)*dx(1) + \ > (inner(grad(v), A1*grad(u)) + v*c + d*u)*dx(2) > L = v*f*dx + v*g*ds > > # Compute solution > A = assemble(a, cell_domains = subdomains) > b = assemble(L) > > U = Function(W) > solve(A, U.vector(), b) > (u, c) = U.split(True) > > print u(0,1) > > So, when I'm in, say iPython types : %run tutorial.py, several times, I get a > different value at point (0,1) each time. > > -- > You received this question notification because you are a member of > DOLFIN Team, which is an answer contact for DOLFIN. > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
