## [e85390]: inst / example / Mixed-Poisson / MixedPoisson.m Maximize Restore History

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44``` ```## Copyright (C) 2013 Marco Vassallo ## ## This program is free software; you can redistribute it and/or modify it under ## the terms of the GNU General Public License as published by the Free Software ## Foundation; either version 3 of the License, or (at your option) any later ## version. ## ## This program is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more ## details. ## ## You should have received a copy of the GNU General Public License along with ## this program; if not, see . pkg load fem-fenics msh import_ufl_Problem ('MixedPoisson') # Create mesh x = y = linspace (0, 1, 33); mesh = Mesh(msh2m_structured_mesh (x, y, 1, 1:4)); V = FunctionSpace('MixedPoisson', mesh); f = Expression ('f', @(x,y) 10*exp(-((x - 0.5)^2 + (y - 0.5)^2) / 0.02)); a = BilinearForm ('MixedPoisson', V, V); L = LinearForm ('MixedPoisson', V, f); # Define essential boundary bc1 = DirichletBC (SubSpace (V, 1), @(x,y) [0; -sin(5.0*x)], 1); bc2 = DirichletBC (SubSpace (V, 1), @(x,y) [0; sin(5.0*x)], 3); # Compute solution [A, b] = assemble_system (a, L, bc1, bc2); sol = A \ b; func = Function ('func', V, sol); sigma = Function ('sigma', func, 1); u = Function ('u', func, 2); # Plot solution plot (sigma); plot (u); ```