# -*- coding: utf-8 -*-
"""
Created on Tue Oct 28 09:50:33 2014

@author: hans-werner
"""

from dolfin import *

#
# Mesh
# 
mesh = Mesh("potential_flow_domain01.xml")
V = FunctionSpace(mesh,"CG",1)

#
# Specify different parts of the boundary
#
potential_left = Constant(0.0)

def boundary_left(x,on_boundary):
  return abs(x[0]) < DOLFIN_EPS and on_boundary

bc_left = DirichletBC(V,potential_left,boundary_left)
           
potential_right = Constant(10.0)

def boundary_right(x,on_boundary):
  return  abs(x[0] - 10.0) < DOLFIN_EPS and \
           x[1] >= -1.0 and \
           x[1] <=  0.0 and \
           on_boundary 

bc_right = DirichletBC(V,potential_right,boundary_right)
 
bc = [bc_left,bc_right]
                 
#
# Set up the bilinear form
#
u = TrialFunction(V)
v = TestFunction(V)

a = inner(grad(u),grad(v))*dx
L = Constant(0.0)*v*dx

u = Function(V)
solve(a == L, u, bc)


u_vel = grad(u) 

plot(u)
plot(u_vel)

interactive()

file = File('potential_flow_01.pvd')
file << u