Commit: 5f3b4941f4485411daafa5c3a42017647da24277 - myprojects-hg-reborn (hg)

Commit MetaInfo

• Révision: 5f3b4941f4485411daafa5c3a42017647da24277 (tree)
• l'heure: 2007-11-06 18:03:33
• Auteur: iselllo
• Commiter: iselllo

Message de Log

I added the code dolfin_demo.py which solves Poisson equation on a 2D
box using the finite-element code dolfin.

Change Summary

• add: Python-codes/dolfin_demo.py

Modification

diff -r 298da147ec24 -r 5f3b4941f448 Python-codes/dolfin_demo.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Python-codes/dolfin_demo.py	Tue Nov 06 09:03:33 2007 +0000
@@ -0,0 +1,54 @@
+#! /usr/bin/env python
+
+from dolfin import *
+
+# Create mesh and finite element
+mesh = UnitSquare(32, 32)
+element = FiniteElement("Lagrange", "triangle", 1)
+
+# Source term
+class Source(Function):
+    def __init__(self, element, mesh):
+        Function.__init__(self, element, mesh)
+    def eval(self, values, x):
+        dx = x[0] - 0.5
+        dy = x[1] - 0.5
+        values[0] = 500.0*exp(-(dx*dx + dy*dy)/0.02)
+
+# Neumann boundary condition
+class Flux(Function):
+    def __init__(self, element, mesh):
+        Function.__init__(self, element, mesh)
+    def eval(self, values, x):
+        if x[0] > DOLFIN_EPS:
+            values[0] = 25.0*sin(5.0*DOLFIN_PI*x[1])
+        else:
+            values[0] = 0.0
+
+# Sub domain for Dirichlet boundary condition
+class DirichletBoundary(SubDomain):
+    def inside(self, x, on_boundary):
+        return bool(on_boundary and x[0] < DOLFIN_EPS)
+
+# Define variational problem
+v = TestFunction(element)
+u = TrialFunction(element)
+f = Source(element, mesh)
+g = Flux(element, mesh)
+
+a = dot(grad(v), grad(u))*dx
+L = v*f*dx + v*g*ds
+
+# Define boundary condition
+u0 = Function(mesh, 0.0)
+boundary = DirichletBoundary()
+bc = DirichletBC(u0, mesh, boundary)
+
+# Solve PDE and plot solution
+pde = LinearPDE(a, L, mesh, bc)
+u = pde.solve()
+plot(u)
+
+# Save solution to file
+file = File("poisson.pvd")
+file << u