Files
simpeg/code/getDIV.py
T
SEOGI KANG 18fd590eff Generating 3D divergence matrix: getDIV.py
Some funtions for sparse matrix: sputils.py -> Updated we've discussed before
Test example for divergence
2013-07-10 17:10:54 -07:00

76 lines
1.9 KiB
Python

import numpy as np
from scipy import sparse
from utils import mkvc
from sputils import ddx, sdiag, speye, kron3
def getvol(h):
# Cell sizes in each direction
h1 = h[0]
h2 = h[1]
h3 = h[2]
# Compute cell volumes
v12 = h1.T*h2
V = mkvc(v12.reshape(-1,1)*h3)
return V
def getarea(h):
# Cell sizes in each direction
h1 = h[0]
h2 = h[1]
h3 = h[2]
# The number of cell centers in each direction
n1 = np.size(h1)
n2 = np.size(h2)
n3 = np.size(h3)
# Compute areas of cell faces
area1 = np.ones((n1+1,1))*mkvc(h2.T*h3)
area2 = h1.T*mkvc(np.ones((n2+1,1))*h3)
area3 = h1.T*mkvc(h2.T*np.ones(n3+1))
area = np.hstack((np.hstack((mkvc(area1), mkvc(area2))), mkvc(area3)))
return area
def getDivMatrix(h):
"""Consturct the 3D divergence operator on Faces."""
# Cell sizes in each direction
h1 = h[0]
h2 = h[1]
h3 = h[2]
# The number of cell centers in each direction
n1 = np.size(h1)
n2 = np.size(h2)
n3 = np.size(h3)
# Compute areas of cell faces
#area1 = np.ones((n1+1,1))*mkvc(h2.T*h3)
#area2 = h1.T*mkvc(np.ones((n2+1,1))*h3)
#area3 = h1.T*mkvc(h2.T*np.ones(n3+1))
#area = np.hstack((np.hstack((mkvc(area1), mkvc(area2))), mkvc(area3)))
area = getarea(h)
S = sdiag(area)
# Compute cell volumes
#v12 = h1.T*h2
#V = mkvc(v12.reshape(-1,1)*h3)
V = getvol(h)
# Compute divergence operator on faces
d1 = ddx(n1)
d2 = ddx(n2)
d3 = ddx(n3)
D1 = kron3(speye(n3), speye(n2), d1)
D2 = kron3(speye(n3), d2, speye(n1))
D3 = kron3(d3, speye(n2), speye(n1))
D = sparse.hstack((sparse.hstack((D1, D2)), D3))
return sdiag(1/V)*D*S