# -*- coding: utf-8 -*-
"""
Created on Wed Jan 27 14:46:47 2016

@author: ddesantis
"""

from fipy import CellVariable, Gmsh2D, TransientTerm, DiffusionTerm, Viewer
from fipy.tools import numerix


cellSize = 0.05
radius = 1.
mesh = Gmsh2D('''
...               cellSize = %(cellSize)g;
...               radius = %(radius)g;
...               Point(1) = {0, 0, 0, cellSize};
...               Point(2) = {-radius, 0, 0, cellSize};
...               Point(3) = {0, radius, 0, cellSize};
...               Point(4) = {radius, 0, 0, cellSize};
...               Point(5) = {0, -radius, 0, cellSize};
...               Circle(6) = {2, 1, 3};
...               Circle(7) = {3, 1, 4};
...               Circle(8) = {4, 1, 5};
...               Circle(9) = {5, 1, 2};
...               Line Loop(10) = {6, 7, 8, 9};
...               Plane Surface(11) = {10};
...               ''' % locals()) # doctest: +GMSH


"""
phi = CellVariable(name = "solution variable",mesh=mesh, value =0.)

viewer = None
if __name__ == '__main__':
    try:
        viewer = Viewer(var=phi,datamin=-1,datamax=1.)
        viewer.plotMesh()
        raw_input("Irregular circular mesh. press <return> to proceed...")
    except:
            print "unable to create a viewer for an irregular mesh (try Gist)2DViewer, Matplotlib2Dviewer, or MayaviViewer)"
            
D = 1.
eq = TransientTerm() == DiffusionTerm(coeff=D)

X,Y = mesh.faceCenters

phi.constrain(X, mesh.exteriorFaces)

timeStepDuration = 10 * 0.9 * cellSize**2 / (2*D)
steps = 10
for step in range(steps):
    eq.solve(var=phi, dt=timeStepDuration)
    if viewer is not Note:
        viewer.plot()
        
"""