def interp(self, y, eigvals, eigvectors, eigval=1, verbose=False):
"""Interpolate solution eigenvector and it's derivative onto y
Parameters
----------
y : array
Interpolation points
eigvals : array
All computed eigenvalues
eigvectors : array
All computed eigenvectors
eigval : int, optional
The chosen eigenvalue, ranked with descending imaginary
part. The largest imaginary part is 1, the second
largest is 2, etc.
verbose : bool, optional
Print information or not
"""
N = self.N
nx, eigval = self.get_eigval(eigval, eigvals, verbose)
phi_hat = np.zeros(N, np.complex)
phi_hat[:-4] = np.squeeze(eigvectors[:, nx])
if not len(self.P4) == len(y):
SB = Basis(N, 'C', bc='Biharmonic', quad=self.quad)
self.P4 = SB.evaluate_basis_all(x=y)
self.T4x = SB.evaluate_basis_derivative_all(x=y, k=1)
phi = np.dot(self.P4, phi_hat)
dphidy = np.dot(self.T4x, phi_hat)
return eigval, phi, dphidy
def test_project_hermite(typecode, dim):
# Using sympy to compute an analytical solution
x, y, z = symbols("x,y,z")
sizes = (20, 19)
funcs = {
(1, 0): (cos(4*y)*sin(2*x))*exp(-x**2/2),
(1, 1): (cos(4*x)*sin(2*y))*exp(-y**2/2),
(2, 0): (sin(3*z)*cos(4*y)*sin(2*x))*exp(-x**2/2),
(2, 1): (sin(2*z)*cos(4*x)*sin(2*y))*exp(-y**2/2),
(2, 2): (sin(2*x)*cos(4*y)*sin(2*z))*exp(-z**2/2)
}
xs = {0:x, 1:y, 2:z}
for shape in product(*([sizes]*dim)):
bases = []
for n in shape[:-1]:
bases.append(Basis(n, 'F', dtype=typecode.upper()))
bases.append(Basis(shape[-1], 'F', dtype=typecode))
for axis in range(dim+1):
ST0 = hBasis[0](3*shape[-1])
bases.insert(axis, ST0)
fft = TensorProductSpace(comm, bases, dtype=typecode, axes=axes[dim][axis])
X = fft.local_mesh(True)
ue = funcs[(dim, axis)]
due = ue.diff(xs[0], 1)
u_h = project(ue, fft)
du_h = project(due, fft)
du2 = project(Dx(u_h, 0, 1), fft)
assert np.linalg.norm(du_h-du2) < 1e-5
bases.pop(axis)
fft.destroy()
def assemble(self):
N = self.N
SB = Basis(N, 'C', bc='Biharmonic', quad=self.quad)
SB.plan((N, N), 0, np.float, {})
# (u'', v)
K = inner_product((SB, 0), (SB, 2))
# ((1-x**2)u, v)
x = sp.symbols('x', real=True)
K1 = inner_product((SB, 0), (SB, 0), measure=(1-x**2))
# ((1-x**2)u'', v)
K2 = inner_product((SB, 0), (SB, 2), measure=(1-x**2))
# (u'''', v)
Q = inner_product((SB, 0), (SB, 4))
# (u, v)
M = inner_product((SB, 0), (SB, 0))
Re = self.Re
a = self.alfa
B = -Re*a*1j*(K-a**2*M)
A = Q-2*a**2*K+a**4*M - 2*a*Re*1j*M - 1j*a*Re*(K2-a**2*K1)
return A.diags().toarray(), B.diags().toarray()
def interp(self, y, eigvals, eigvectors, eigval=1, verbose=False):
"""Interpolate solution eigenvector and it's derivative onto y
Parameters
----------
y : array
Interpolation points
eigvals : array
All computed eigenvalues
eigvectors : array
All computed eigenvectors
eigval : int, optional
The chosen eigenvalue, ranked with descending imaginary
part. The largest imaginary part is 1, the second
largest is 2, etc.
verbose : bool, optional
Print information or not
"""
N = self.N
nx, eigval = self.get_eigval(eigval, eigvals, verbose)
phi_hat = np.zeros(N, np.complex)
phi_hat[:-4] = np.squeeze(eigvectors[:, nx])
if not len(self.P4) == len(y):
SB = Basis(N, 'C', bc='Biharmonic', quad=self.quad)
self.P4 = SB.evaluate_basis_all(x=y)
self.T4x = SB.evaluate_basis_derivative_all(x=y, k=1)
phi = np.dot(self.P4, phi_hat)
dphidy = np.dot(self.T4x, phi_hat)
return eigval, phi, dphidy
def test_biharmonic2D(family, axis):
la = lla
if family == 'chebyshev':
la = cla
N = (16, 16)
SD = Basis(N[axis], family=family, bc='Biharmonic')
K1 = Basis(N[(axis + 1) % 2], family='F', dtype='d')
subcomms = mpi4py_fft.pencil.Subcomm(MPI.COMM_WORLD, allaxes2D[axis])
bases = [K1]
bases.insert(axis, SD)
T = TensorProductSpace(subcomms, bases, axes=allaxes2D[axis])
u = TrialFunction(T)
v = TestFunction(T)
if family == 'chebyshev':
mat = inner(v, div(grad(div(grad(u)))))
else:
mat = inner(div(grad(v)), div(grad(u)))
H = la.Biharmonic(*mat)
u = Function(T)
u[:] = np.random.random(u.shape) + 1j * np.random.random(u.shape)
f = Function(T)
f = H.matvec(u, f)
g0 = Function(T)
g1 = Function(T)
g2 = Function(T)
M = {d.get_key(): d for d in mat}
g0 = M['SBBmat'].matvec(u, g0)
g1 = M['ABBmat'].matvec(u, g1)
g2 = M['BBBmat'].matvec(u, g2)
assert np.linalg.norm(f - (g0 + g1 + g2)) < 1e-8
def test_shentransform(typecode, dim, ST, quad):
for shape in product(*([sizes] * dim)):
bases = []
for n in shape[:-1]:
bases.append(Basis(n, 'F', dtype=typecode.upper()))
bases.append(Basis(shape[-1], 'F', dtype=typecode))
if dim < 3:
n = min(shape)
if typecode in 'fdg':
n //= 2
n += 1
if n < comm.size:
continue
for axis in range(dim + 1):
ST0 = ST(shape[-1], quad=quad)
bases.insert(axis, ST0)
fft = TensorProductSpace(comm, bases, dtype=typecode)
U = random_like(fft.forward.input_array)
F = fft.forward(U)
Fc = F.copy()
V = fft.backward(F)
F = fft.forward(U)
assert allclose(F, Fc)
bases.pop(axis)
fft.destroy()
def test_project(typecode, dim, ST, quad):
# Using sympy to compute an analytical solution
x, y, z = symbols("x,y,z")
sizes = (25, 24)
funcs = {
(1, 0): (cos(4 * y) * sin(2 * np.pi * x)) * (1 - x**2),
(1, 1): (cos(4 * x) * sin(2 * np.pi * y)) * (1 - y**2),
(2, 0): (sin(6 * z) * cos(4 * y) * sin(2 * np.pi * x)) * (1 - x**2),
(2, 1): (sin(2 * z) * cos(4 * x) * sin(2 * np.pi * y)) * (1 - y**2),
(2, 2): (sin(2 * x) * cos(4 * y) * sin(2 * np.pi * z)) * (1 - z**2)
}
syms = {1: (x, y), 2: (x, y, z)}
xs = {0: x, 1: y, 2: z}
for shape in product(*([sizes] * dim)):
bases = []
for n in shape[:-1]:
bases.append(Basis(n, 'F', dtype=typecode.upper()))
bases.append(Basis(shape[-1], 'F', dtype=typecode))
if dim < 3:
n = min(shape)
if typecode in 'fdg':
n //= 2
n += 1
if n < comm.size:
continue
for axis in range(dim + 1):
ST0 = ST(shape[-1], quad=quad)
bases.insert(axis, ST0)
fft = TensorProductSpace(comm,
bases,
dtype=typecode,
axes=axes[dim][axis])
X = fft.local_mesh(True)
ue = funcs[(dim, axis)]
ul = lambdify(syms[dim], ue, 'numpy')
uq = ul(*X).astype(typecode)
uh = Function(fft)
uh = fft.forward(uq, uh)
due = ue.diff(xs[axis], 1)
dul = lambdify(syms[dim], due, 'numpy')
duq = dul(*X).astype(typecode)
uf = project(Dx(uh, axis, 1), fft)
uy = Array(fft)
uy = fft.backward(uf, uy)
assert np.allclose(uy, duq, 0, 1e-6)
for ax in (x for x in range(dim + 1) if x is not axis):
due = ue.diff(xs[axis], 1, xs[ax], 1)
dul = lambdify(syms[dim], due, 'numpy')
duq = dul(*X).astype(typecode)
uf = project(Dx(Dx(uh, axis, 1), ax, 1), fft)
uy = Array(fft)
uy = fft.backward(uf, uy)
assert np.allclose(uy, duq, 0, 1e-6)
bases.pop(axis)
fft.destroy()
def test_curl(typecode):
K0 = Basis(N[0], 'F', dtype=typecode.upper())
K1 = Basis(N[1], 'F', dtype=typecode.upper())
K2 = Basis(N[2], 'F', dtype=typecode)
T = TensorProductSpace(comm, (K0, K1, K2), dtype=typecode)
X = T.local_mesh(True)
K = T.local_wavenumbers()
Tk = VectorTensorProductSpace(T)
u = TrialFunction(Tk)
v = TestFunction(Tk)
U = Array(Tk)
U_hat = Function(Tk)
curl_hat = Function(Tk)
curl_ = Array(Tk)
# Initialize a Taylor Green vortex
U[0] = np.sin(X[0]) * np.cos(X[1]) * np.cos(X[2])
U[1] = -np.cos(X[0]) * np.sin(X[1]) * np.cos(X[2])
U[2] = 0
U_hat = Tk.forward(U, U_hat)
Uc = U_hat.copy()
U = Tk.backward(U_hat, U)
U_hat = Tk.forward(U, U_hat)
assert allclose(U_hat, Uc)
divu_hat = project(div(U_hat), T)
divu = Array(T)
divu = T.backward(divu_hat, divu)
assert allclose(divu, 0)
curl_hat[0] = 1j * (K[1] * U_hat[2] - K[2] * U_hat[1])
curl_hat[1] = 1j * (K[2] * U_hat[0] - K[0] * U_hat[2])
curl_hat[2] = 1j * (K[0] * U_hat[1] - K[1] * U_hat[0])
curl_ = Tk.backward(curl_hat, curl_)
w_hat = Function(Tk)
w_hat = inner(v, curl(U_hat), output_array=w_hat)
A = inner(v, u)
for i in range(3):
w_hat[i] = A[i].solve(w_hat[i])
w = Array(Tk)
w = Tk.backward(w_hat, w)
#from IPython import embed; embed()
assert allclose(w, curl_)
u_hat = Function(Tk)
u_hat = inner(v, U, output_array=u_hat)
for i in range(3):
u_hat[i] = A[i].solve(u_hat[i])
uu = Array(Tk)
uu = Tk.backward(u_hat, uu)
assert allclose(u_hat, U_hat)
def test_curl2():
# Test projection of curl
K0 = Basis(N[0], 'C', bc=(0, 0))
K1 = Basis(N[1], 'F', dtype='D')
K2 = Basis(N[2], 'F', dtype='d')
K3 = Basis(N[0], 'C')
T = TensorProductSpace(comm, (K0, K1, K2))
TT = TensorProductSpace(comm, (K3, K1, K2))
X = T.local_mesh(True)
K = T.local_wavenumbers(False)
Tk = VectorTensorProductSpace(T)
TTk = MixedTensorProductSpace([T, T, TT])
U = Array(Tk)
U_hat = Function(Tk)
curl_hat = Function(TTk)
curl_ = Array(TTk)
# Initialize a Taylor Green vortex
U[0] = np.sin(X[0]) * np.cos(X[1]) * np.cos(X[2]) * (1 - X[0]**2)
U[1] = -np.cos(X[0]) * np.sin(X[1]) * np.cos(X[2]) * (1 - X[0]**2)
U[2] = 0
U_hat = Tk.forward(U, U_hat)
Uc = U_hat.copy()
U = Tk.backward(U_hat, U)
U_hat = Tk.forward(U, U_hat)
assert allclose(U_hat, Uc)
# Compute curl first by computing each term individually
curl_hat[0] = 1j * (K[1] * U_hat[2] - K[2] * U_hat[1])
curl_[0] = T.backward(
curl_hat[0], curl_[0]) # No x-derivatives, still in Dirichlet space
dwdx_hat = project(Dx(U_hat[2], 0, 1), TT) # Need to use space without bc
dvdx_hat = project(Dx(U_hat[1], 0, 1), TT) # Need to use space without bc
dwdx = Array(TT)
dvdx = Array(TT)
dwdx = TT.backward(dwdx_hat, dwdx)
dvdx = TT.backward(dvdx_hat, dvdx)
curl_hat[1] = 1j * K[2] * U_hat[0]
curl_hat[2] = -1j * K[1] * U_hat[0]
curl_[1] = T.backward(curl_hat[1], curl_[1])
curl_[2] = T.backward(curl_hat[2], curl_[2])
curl_[1] -= dwdx
curl_[2] += dvdx
# Now do it with project
w_hat = project(curl(U_hat), TTk)
w = Array(TTk)
w = TTk.backward(w_hat, w)
assert allclose(w, curl_)
def interp(self, y, eigvals, eigvectors, eigval=1, verbose=False):
"""Interpolate solution eigenvector and it's derivative onto y
Parameters
----------
y : array
Interpolation points
eigvals : array
All computed eigenvalues
eigvectors : array
All computed eigenvectors
eigval : int, optional
The chosen eigenvalue, ranked with descending imaginary
part. The largest imaginary part is 1, the second
largest is 2, etc.
verbose : bool, optional
Print information or not
"""
nx, eigval = self.get_eigval(eigval, eigvals, verbose)
SB = Basis(self.N, 'C', bc='Biharmonic', quad=self.quad, dtype='D')
phi_hat = Function(SB)
phi_hat[:-4] = np.squeeze(eigvectors[:, nx])
phi = phi_hat.eval(y)
dphidy = Dx(phi_hat, 0, 1).eval(y)
return eigval, phi, dphidy
def test_project(typecode, dim, ST, quad):
# Using sympy to compute an analytical solution
x, y, z = symbols("x,y,z")
sizes = (20, 19)
funcs = {
(1, 0): (cos(1*y)*sin(1*np.pi*x))*(1-x**2),
(1, 1): (cos(1*x)*sin(1*np.pi*y))*(1-y**2),
(2, 0): (sin(1*z)*cos(1*y)*sin(1*np.pi*x))*(1-x**2),
(2, 1): (sin(1*z)*cos(1*x)*sin(1*np.pi*y))*(1-y**2),
(2, 2): (sin(1*x)*cos(1*y)*sin(1*np.pi*z))*(1-z**2)
}
xs = {0:x, 1:y, 2:z}
for shape in product(*([sizes]*dim)):
bases = []
for n in shape[:-1]:
bases.append(Basis(n, 'F', dtype=typecode.upper()))
bases.append(Basis(shape[-1], 'F', dtype=typecode))
for axis in range(dim+1):
ST0 = ST(shape[-1], quad=quad)
bases.insert(axis, ST0)
fft = TensorProductSpace(comm, bases, dtype=typecode, axes=axes[dim][axis])
dfft = fft.get_orthogonal()
X = fft.local_mesh(True)
ue = funcs[(dim, axis)]
uq = Array(fft, buffer=ue)
uh = Function(fft)
uh = fft.forward(uq, uh)
due = ue.diff(xs[axis], 1)
duq = Array(fft, buffer=due)
uf = project(Dx(uh, axis, 1), dfft).backward()
assert np.linalg.norm(uf-duq) < 1e-5
for ax in (x for x in range(dim+1) if x is not axis):
due = ue.diff(xs[axis], 1, xs[ax], 1)
duq = Array(fft, buffer=due)
uf = project(Dx(Dx(uh, axis, 1), ax, 1), dfft).backward()
assert np.linalg.norm(uf-duq) < 1e-5
bases.pop(axis)
fft.destroy()
dfft.destroy()
def assemble(self):
N = self.N
SB = Basis(N, 'C', bc='Biharmonic', quad=self.quad)
SB.plan((N, N), 0, np.float, {})
x, _ = self.x, self.w = SB.points_and_weights(N)
# Trial function
P4 = SB.evaluate_basis_all(x=x)
# Second derivatives
T2x = SB.evaluate_basis_derivative_all(x=x, k=2)
# (u'', v)
K = np.zeros((N, N))
K[:-4, :-4] = inner_product((SB, 0), (SB, 2)).diags().toarray()
# ((1-x**2)u, v)
xx = np.broadcast_to((1 - x**2)[:, np.newaxis], (N, N))
#K1 = np.dot(w*P4.T, xx*P4) # Alternative: K1 = np.dot(w*P4.T, ((1-x**2)*P4.T).T)
K1 = np.zeros((N, N))
K1 = SB.scalar_product(xx * P4, K1)
K1 = extract_diagonal_matrix(
K1).diags().toarray() # For improved roundoff
# ((1-x**2)u'', v)
K2 = np.zeros((N, N))
K2 = SB.scalar_product(xx * T2x, K2)
K2 = extract_diagonal_matrix(
K2).diags().toarray() # For improved roundoff
# (u'''', v)
Q = np.zeros((self.N, self.N))
Q[:-4, :-4] = inner_product((SB, 0), (SB, 4)).diags().toarray()
# (u, v)
M = np.zeros((self.N, self.N))
M[:-4, :-4] = inner_product((SB, 0), (SB, 0)).diags().toarray()
Re = self.Re
a = self.alfa
B = -Re * a * 1j * (K - a**2 * M)
A = Q - 2 * a**2 * K + a**4 * M - 2 * a * Re * 1j * M - 1j * a * Re * (
K2 - a**2 * K1)
return A, B
def test_helmholtz3D(family, axis):
la = lla
if family == 'chebyshev':
la = cla
N = (8, 9, 10)
SD = Basis(N[allaxes3D[axis][0]], family=family, bc=(0, 0))
K1 = Basis(N[allaxes3D[axis][1]], family='F', dtype='D')
K2 = Basis(N[allaxes3D[axis][2]], family='F', dtype='d')
subcomms = mpi4py_fft.pencil.Subcomm(MPI.COMM_WORLD, [0, 1, 1])
bases = [0] * 3
bases[allaxes3D[axis][0]] = SD
bases[allaxes3D[axis][1]] = K1
bases[allaxes3D[axis][2]] = K2
T = TensorProductSpace(subcomms, bases, axes=allaxes3D[axis])
u = TrialFunction(T)
v = TestFunction(T)
if family == 'chebyshev':
mat = inner(v, div(grad(u)))
else:
mat = inner(grad(v), grad(u))
H = la.Helmholtz(*mat)
u = Function(T)
s = SD.sl[SD.slice()]
u[s] = np.random.random(u[s].shape) + 1j * np.random.random(u[s].shape)
f = Function(T)
f = H.matvec(u, f)
g0 = Function(T)
g1 = Function(T)
M = {d.get_key(): d for d in mat}
g0 = M['ADDmat'].matvec(u, g0)
g1 = M['BDDmat'].matvec(u, g1)
assert np.linalg.norm(f - (g0 + g1)) < 1e-12, np.linalg.norm(f - (g0 + g1))
uc = Function(T)
uc = H(uc, f)
assert np.linalg.norm(uc - u) < 1e-12
def test_mul2():
mat = SparseMatrix({0: 1}, (3, 3))
v = np.ones(3)
c = mat * v
assert np.allclose(c, 1)
mat = SparseMatrix({-2: 1, -1: 1, 0: 1, 1: 1, 2: 1}, (3, 3))
c = mat * v
assert np.allclose(c, 3)
SD = Basis(8, "L", bc=(0, 0), scaled=True)
u = TrialFunction(SD)
v = TestFunction(SD)
mat = inner(grad(u), grad(v))
z = Function(SD, val=1)
c = mat * z
assert np.allclose(c[:6], 1)
def assemble(self):
N = self.N
SB = Basis(N, 'C', bc='Biharmonic', quad=self.quad)
SB.plan((N, N), 0, np.float, {})
x, _ = self.x, self.w = SB.points_and_weights(N)
# Trial function
P4 = SB.evaluate_basis_all(x=x)
# Second derivatives
T2x = SB.evaluate_basis_derivative_all(x=x, k=2)
# (u'', v)
K = np.zeros((N, N))
K[:-4, :-4] = inner_product((SB, 0), (SB, 2)).diags().toarray()
# ((1-x**2)u, v)
xx = np.broadcast_to((1-x**2)[:, np.newaxis], (N, N))
#K1 = np.dot(w*P4.T, xx*P4) # Alternative: K1 = np.dot(w*P4.T, ((1-x**2)*P4.T).T)
K1 = np.zeros((N, N))
K1 = SB.scalar_product(xx*P4, K1)
K1 = extract_diagonal_matrix(K1).diags().toarray() # For improved roundoff
# ((1-x**2)u'', v)
K2 = np.zeros((N, N))
K2 = SB.scalar_product(xx*T2x, K2)
K2 = extract_diagonal_matrix(K2).diags().toarray() # For improved roundoff
# (u'''', v)
Q = np.zeros((self.N, self.N))
Q[:-4, :-4] = inner_product((SB, 0), (SB, 4)).diags().toarray()
# (u, v)
M = np.zeros((self.N, self.N))
M[:-4, :-4] = inner_product((SB, 0), (SB, 0)).diags().toarray()
Re = self.Re
a = self.alfa
B = -Re*a*1j*(K-a**2*M)
A = Q-2*a**2*K+a**4*M - 2*a*Re*1j*M - 1j*a*Re*(K2-a**2*K1)
return A, B
