In [5]:

    

import petsc4py
import sys

petsc4py.init(sys.argv)

from petsc4py import PETSc
import mshr
from dolfin import *
import sympy as sy
import numpy as np
import ExactSol
import MatrixOperations as MO
import CheckPetsc4py as CP

n = 4
# domain = mshr.Rectangle(Point(-1., -1.), Point(1., 1.)) - mshr.Rectangle(Point(0., -1.), Point(1., 0.) )
# mesh = mshr.generate_mesh(domain, n)
mesh = RectangleMesh(-1,-1,1,1,n,n, 'crossed')
cell_f = CellFunction('size_t', mesh, 0)
for cell in cells(mesh):
    v = cell.get_vertex_coordinates()
    y = v[np.arange(0,6,2)]
    x = v[np.arange(1,6,2)]
    xone = np.ones(3)
    xone[x > 0] = 0
    yone = np.ones(3)
    yone[y < 0] = 0
    if np.sum(xone)+ np.sum(yone)>5.5:
        cell_f[cell] = 1
mesh = SubMesh(mesh, cell_f, 0)


    

In [6]:

    

plot(mesh)


    

    
Out[6]:





<dolfin.cpp.io.VTKPlotter; proxy of <Swig Object of type 'std::shared_ptr< dolfin::VTKPlotter > *' at 0x113e21e70> >

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