Files
simpeg/SimPEG/DiffOperators.py
T
Rowan Cockett 26b334585f EdgeInnerProducts now working for LOM
Fixed DiffOps bug in CURL

Fixed bug in OrderTest --> must remember to do cumSum, and not just supply dx to ndgrid

test_massMatrices now tests uniformLOM
2013-08-03 16:39:34 -07:00

303 lines
12 KiB
Python

import numpy as np
from scipy import sparse as sp
from sputils import sdiag, speye, kron3, spzeros
from utils import mkvc
def ddx(n):
"""Define 1D derivatives, inner, this means we go from n+1 to n+1"""
return sp.spdiags((np.ones((n+1, 1))*[-1, 1]).T, [0, 1], n, n+1, format="csr")
def checkBC(bc):
""" Checks if boundary condition 'bc' is valid. """
if(type(bc) is str):
bc = [bc, bc]
assert type(bc) is list, 'bc must be a list'
assert len(bc) == 2, 'bc must have two elements'
for bc_i in bc:
assert type(bc_i) is str, "each bc must be a string"
assert bc_i in ['dirichlet', 'neumann'], "each bc must be either, 'dirichlet' or 'neumann'"
return bc
def ddxCellGrad(n, bc):
"""Create 1D derivative operator from cell-centres to nodes this means we go from n to n+1"""
bc = checkBC(bc)
D = sp.spdiags((np.ones((n+1, 1))*[-1, 1]).T, [-1, 0], n+1, n, format="csr")
# Set the first side
if(bc[0] == 'dirichlet'):
D[0, 0] = 2
elif(bc[0] == 'neumann'):
D[0, 0] = 0
# Set the second side
if(bc[1] == 'dirichlet'):
D[-1, -1] = -2
elif(bc[1] == 'neumann'):
D[-1, -1] = 0
return D
def av(n):
"""Define 1D averaging operator from cell-centres to nodes."""
return sp.spdiags((0.5*np.ones((n+1, 1))*[1, 1]).T, [0, 1], n, n+1, format="csr")
class DiffOperators(object):
"""
Class creates the differential operators that you need!
"""
def __init__(self):
raise Exception('DiffOperators is a base class providing differential operators on meshes and cannot run on its own. Inherit to your favorite Mesh class.')
def faceDiv():
doc = "Construct divergence operator (face-stg to cell-centres)."
def fget(self):
if(self._faceDiv is None):
# The number of cell centers in each direction
n = self.n
# Compute faceDivergence operator on faces
if(self.dim == 1):
D = ddx(n[0])
elif(self.dim == 2):
D1 = sp.kron(speye(n[1]), ddx(n[0]))
D2 = sp.kron(ddx(n[1]), speye(n[0]))
D = sp.hstack((D1, D2), format="csr")
elif(self.dim == 3):
D1 = kron3(speye(n[2]), speye(n[1]), ddx(n[0]))
D2 = kron3(speye(n[2]), ddx(n[1]), speye(n[0]))
D3 = kron3(ddx(n[2]), speye(n[1]), speye(n[0]))
D = sp.hstack((D1, D2, D3), format="csr")
# Compute areas of cell faces & volumes
S = self.area
V = self.vol
self._faceDiv = sdiag(1/V)*D*sdiag(S)
return self._faceDiv
return locals()
_faceDiv = None
faceDiv = property(**faceDiv())
def nodalGrad():
doc = "Construct gradient operator (nodes to edges)."
def fget(self):
if(self._nodalGrad is None):
# The number of cell centers in each direction
n = self.n
# Compute divergence operator on faces
if(self.dim == 1):
G = ddx(n[0])
elif(self.dim == 2):
D1 = sp.kron(speye(n[1]+1), ddx(n[0]))
D2 = sp.kron(ddx(n[1]), speye(n[0]+1))
G = sp.vstack((D1, D2), format="csr")
elif(self.dim == 3):
D1 = kron3(speye(n[2]+1), speye(n[1]+1), ddx(n[0]))
D2 = kron3(speye(n[2]+1), ddx(n[1]), speye(n[0]+1))
D3 = kron3(ddx(n[2]), speye(n[1]+1), speye(n[0]+1))
G = sp.vstack((D1, D2, D3), format="csr")
# Compute lengths of cell edges
L = self.edge
self._nodalGrad = sdiag(1/L)*G
return self._nodalGrad
return locals()
_nodalGrad = None
nodalGrad = property(**nodalGrad())
def setCellGradBC(self, BC):
"""
Function that sets the boundary conditions for cell-centred derivative operators.
Examples:
BC = 'neumann' # Neumann in all directions
BC = ['neumann', 'dirichlet', 'neumann'] # 3D, Dirichlet in y Neumann else
BC = [['neumann', 'dirichlet'], 'dirichlet', 'dirichlet'] # 3D, Neumann in x on bottom of domain,
# Dirichlet else
"""
if(type(BC) is str):
BC = [BC for _ in self.n] # Repeat the str self.dim times
elif(type(BC) is list):
assert len(BC) == self.dim, 'BC list must be the size of your mesh'
else:
raise Exception("BC must be a str or a list.")
for i, bc_i in enumerate(BC):
BC[i] = checkBC(bc_i)
self._cellGrad = None # ensure we create a new gradient next time we call it
self._cellGradBC = BC
return BC
_cellGradBC = 'neumann'
def cellGrad():
doc = "The cell centered Gradient, takes you to cell faces."
def fget(self):
if(self._cellGrad is None):
BC = self.setCellGradBC(self._cellGradBC)
n = self.n
if(self.dim == 1):
G = ddxCellGrad(n[0], BC[0])
elif(self.dim == 2):
G1 = sp.kron(speye(n[1]), ddxCellGrad(n[0], BC[0]))
G2 = sp.kron(ddxCellGrad(n[1], BC[1]), speye(n[0]))
G = sp.vstack((G1, G2), format="csr")
elif(self.dim == 3):
G1 = kron3(speye(n[2]), speye(n[1]), ddxCellGrad(n[0], BC[0]))
G2 = kron3(speye(n[2]), ddxCellGrad(n[1], BC[1]), speye(n[0]))
G3 = kron3(ddxCellGrad(n[2], BC[2]), speye(n[1]), speye(n[0]))
G = sp.vstack((G1, G2, G3), format="csr")
# Compute areas of cell faces & volumes
S = self.area
V = self.vol
self._cellGrad = sdiag(S)*G*sdiag(1/V)
return self._cellGrad
return locals()
_cellGrad = None
cellGrad = property(**cellGrad())
def edgeCurl():
doc = "Construct the 3D curl operator."
def fget(self):
if(self._edgeCurl is None):
# The number of cell centers in each direction
n1 = self.nCx
n2 = self.nCy
n3 = self.nCy
# Compute lengths of cell edges
L = self.edge
# Compute areas of cell faces
S = self.area
# Compute divergence operator on faces
d1 = ddx(n1)
d2 = ddx(n2)
d3 = ddx(n3)
D32 = kron3(d3, speye(n2), speye(n1+1))
D23 = kron3(speye(n3), d2, speye(n1+1))
D31 = kron3(d3, speye(n2+1), speye(n1))
D13 = kron3(speye(n3), speye(n2+1), d1)
D21 = kron3(speye(n3+1), d2, speye(n1))
D12 = kron3(speye(n3+1), speye(n2), d1)
O1 = spzeros(np.shape(D32)[0], np.shape(D31)[1])
O2 = spzeros(np.shape(D31)[0], np.shape(D32)[1])
O3 = spzeros(np.shape(D21)[0], np.shape(D13)[1])
C = sp.vstack((sp.hstack((O1, -D32, D23)),
sp.hstack((D31, O2, -D13)),
sp.hstack((-D21, D12, O3))), format="csr")
self._edgeCurl = sdiag(1/S)*(C*sdiag(L))
return self._edgeCurl
return locals()
_edgeCurl = None
edgeCurl = property(**edgeCurl())
def faceAve():
doc = "Construct the averaging operator on cell faces to cell centers."
def fget(self):
if(self._faceAve is None):
n = self.n
if(self.dim == 1):
self._faceAve = av(n[0])
elif(self.dim == 2):
self._faceAve = sp.hstack((sp.kron(speye(n[1]), av(n[0])),
sp.kron(av(n[1]), speye(n[0]))), format="csr")
elif(self.dim == 3):
self._faceAve = sp.hstack((kron3(speye(n[2]), speye(n[1]), av(n[0])),
kron3(speye(n[2]), av(n[1]), speye(n[0])),
kron3(av(n[2]), speye(n[1]), speye(n[0]))), format="csr")
return self._faceAve
return locals()
_faceAve = None
faceAve = property(**faceAve())
def edgeAve():
doc = "Construct the averaging operator on cell edges to cell centers."
def fget(self):
if(self._edgeAve is None):
# The number of cell centers in each direction
n = self.n
if(self.dim == 1):
raise Exception('Edge Averaging does not make sense in 1D: Use Identity?')
elif(self.dim == 2):
self._edgeAve = sp.hstack((sp.kron(av(n[1]), speye(n[0])),
sp.kron(speye(n[1]), av(n[0]))), format="csr")
elif(self.dim == 3):
self._edgeAve = sp.hstack((kron3(av(n[2]), av(n[1]), speye(n[0])),
kron3(av(n[2]), speye(n[1]), av(n[0])),
kron3(speye(n[2]), av(n[1]), av(n[0]))), format="csr")
return self._edgeAve
return locals()
_edgeAve = None
edgeAve = property(**edgeAve())
def nodalAve():
doc = "Construct the averaging operator on cell nodes to cell centers."
def fget(self):
if(self._nodalAve is None):
# The number of cell centers in each direction
n = self.n
if(self.dim == 1):
self._nodalAve = av(n[0])
elif(self.dim == 2):
self._nodalAve = sp.hstack((sp.kron(av(n[1]), av(n[0])),
sp.kron(av(n[1]), av(n[0]))), format="csr")
elif(self.dim == 3):
self._nodalAve = sp.hstack((kron3(av(n[2]), av(n[1]), av(n[0])),
kron3(av(n[2]), av(n[1]), av(n[0])),
kron3(av(n[2]), av(n[1]), av(n[0]))), format="csr")
return self._nodalAve
return locals()
_nodalAve = None
nodalAve = property(**nodalAve())
def nodalVectorAve():
doc = "Construct the averaging operator on cell nodes to cell centers, keeping each dimension seperate."
def fget(self):
if(self._nodalVectorAve is None):
# The number of cell centers in each direction
n = self.n
if(self.dim == 1):
self._nodalVectorAve = av(n[0])
elif(self.dim == 2):
self._nodalVectorAve = sp.block_diag((sp.kron(av(n[1]), av(n[0])),
sp.kron(av(n[1]), av(n[0]))), format="csr")
elif(self.dim == 3):
self._nodalVectorAve = sp.block_diag((kron3(av(n[2]), av(n[1]), av(n[0])),
kron3(av(n[2]), av(n[1]), av(n[0])),
kron3(av(n[2]), av(n[1]), av(n[0]))), format="csr")
return self._nodalVectorAve
return locals()
_nodalVectorAve = None
nodalVectorAve = property(**nodalVectorAve())
def getEdgeMass(self, materialProp=None):
"""mass matix for products of edge functions w'*M(materialProp)*e"""
if(materialProp is None):
materialProp = np.ones(self.nC)
Av = self.edgeAve
return sdiag(Av.T * (self.vol * mkvc(materialProp)))
def getFaceMass(self, materialProp=None):
"""mass matix for products of edge functions w'*M(materialProp)*e"""
if(materialProp is None):
materialProp = np.ones(self.nC)
Av = self.faceAve
return sdiag(Av.T*(self.vol*mkvc(materialProp)))