On 27 April 2010 14:18, Anders Logg <[email protected]> wrote:
Any ideas on how to keep the code in the documentation and the actual demos in sync? Should we have a script that copies all the source files? Or should we do the opposite: extract the demos from the documentation?
Good question, initially I thought copying from DOLFIN to documentation was the way to go, but on second thought the other way around might be better. The reason is that if the demos break, then they will be fixed in the documentation which makes is more likely that the accompanying text (and code snippets) will also be corrected. Kristian
-- Anders ---------- Forwarded message ---------- From: [email protected] To: Anders Logg <[email protected]> Date: Tue, 27 Apr 2010 12:01:19 -0000 Subject: [Branch ~fenics-core/fenics-doc/main] Rev 11: Added Poisson.ufl and main.cpp file and create link for download. ------------------------------------------------------------ revno: 11 committer: Kristian B. Ølgaard <[email protected]> branch nick: fenics-doc timestamp: Tue 2010-04-27 13:57:42 +0200 message: Added Poisson.ufl and main.cpp file and create link for download. added: source/demos/cpp/pde/Poisson.ufl source/demos/cpp/pde/poisson_main.cpp modified: source/demos/cpp/pde/cpp_poisson.rst -- lp:fenics-doc https://code.launchpad.net/~fenics-core/fenics-doc/main You are subscribed to branch lp:fenics-doc. To unsubscribe from this branch go to https://code.launchpad.net/~fenics-core/fenics-doc/main/+edit-subscription === added file 'source/demos/cpp/pde/Poisson.ufl' --- source/demos/cpp/pde/Poisson.ufl 1970-01-01 00:00:00 +0000 +++ source/demos/cpp/pde/Poisson.ufl 2010-04-27 11:57:42 +0000 @@ -0,0 +1,20 @@ +# Copyright (C) 2005-2009 Anders Logg. +# Licensed under the GNU LGPL Version 2.1. +# +# First added: 2005 +# Last changed: 2009-09-08 +# +# The bilinear form a(v, u) and linear form L(v) for +# Poisson's equation. +# +# Compile this form with FFC: ffc -l dolfin Poisson.ufl. + +element = FiniteElement("Lagrange", triangle, 1) + +v = TestFunction(element) +u = TrialFunction(element) +f = Coefficient(element) +g = Coefficient(element) + +a = inner(grad(v), grad(u))*dx +L = v*f*dx + v*g*ds === modified file 'source/demos/cpp/pde/cpp_poisson.rst' --- source/demos/cpp/pde/cpp_poisson.rst 2010-04-27 11:12:29 +0000 +++ source/demos/cpp/pde/cpp_poisson.rst 2010-04-27 11:57:42 +0000 @@ -10,7 +10,7 @@ This text is C++ specific -Some UFL code in ``Poisson.h`` +Some UFL code in :download:`Poisson.ufl`. .. code-block:: python @@ -71,3 +71,6 @@ } }; +All this should be in the same :download:`main.cpp<poisson_main.cpp>` file. + + === added file 'source/demos/cpp/pde/poisson_main.cpp' --- source/demos/cpp/pde/poisson_main.cpp 1970-01-01 00:00:00 +0000 +++ source/demos/cpp/pde/poisson_main.cpp 2010-04-27 11:57:42 +0000 @@ -0,0 +1,87 @@ +// Copyright (C) 2006-2009 Anders Logg. +// Licensed under the GNU LGPL Version 2.1. +// +// First added: 2006-02-07 +// Last changed: 2010-04-05 +// +// This demo program solves Poisson's equation +// +// - div grad u(x, y) = f(x, y) +// +// on the unit square with source f given by +// +// f(x, y) = 10*exp(-((x - 0.5)^2 + (y - 0.5)^2) / 0.02) +// +// and boundary conditions given by +// +// u(x, y) = 0 for x = 0 or x = 1 +// du/dn(x, y) = -sin(5*x) for y = 0 or y = 1 + +#include <dolfin.h> +#include "Poisson.h" + +using namespace dolfin; + +// Source term (right-hand side) +class Source : public Expression +{ + void eval(Array<double>& values, const Array<double>& x) const + { + double dx = x[0] - 0.5; + double dy = x[1] - 0.5; + values[0] = 10*exp(-(dx*dx + dy*dy) / 0.02); + } +}; + +// Boundary flux (Neumann boundary condition) +class Flux : public Expression +{ + void eval(Array<double>& values, const Array<double>& x) const + { + values[0] = -sin(5*x[0]); + } +}; + +// Sub domain for Dirichlet boundary condition +class DirichletBoundary : public SubDomain +{ + bool inside(const Array<double>& x, bool on_boundary) const + { + return x[0] < DOLFIN_EPS or x[0] > 1.0 - DOLFIN_EPS; + } +}; + +int main() +{ + // Create mesh and function space + UnitSquare mesh(32, 32); + Poisson::FunctionSpace V(mesh); + + // Define boundary condition + Constant u0(0.0); + DirichletBoundary boundary; + DirichletBC bc(V, u0, boundary); + + // Define variational problem + Poisson::BilinearForm a(V, V); + Poisson::LinearForm L(V); + Source f; + Flux g; + L.f = f; + L.g = g; + + // Compute solution + VariationalProblem problem(a, L, bc); + problem.parameters["linear_solver"] = "iterative"; + Function u(V); + problem.solve(u); + + // Save solution in VTK format + File file("poisson.pvd"); + file << u; + + // Plot solution + plot(u); + + return 0; +} -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkvW1i0ACgkQTuwUCDsYZdGwLgCdFPgbJke73i5QHWPo50NaQXxU 6cEAniYG20A/l8GYI389W10WZng8P7Vb =ik1b -----END PGP SIGNATURE----- _______________________________________________ Mailing list: https://launchpad.net/~fenics Post to : [email protected] Unsubscribe : https://launchpad.net/~fenics More help : https://help.launchpad.net/ListHelp
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