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

Download this file

MixedPoisson.m    45 lines (35 with data), 1.5 kB

 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 <gedeone-octave@users.sourceforge.net>
##
## 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 <http://www.gnu.org/licenses/>.
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);