def test_chebyshev_iteration_1(self):
''' Tests the pcd_shell operators produce correct output. '''
A = self.quad_mass_matrix
n = self.quad_mass_matrix.shape[0]
alpha = 1. / 4
beta = 9. / 4
x0 = np.zeros(n)
b1 = np.ones(n)
for i in range(0, n, 2):
b1[i] = 0.
A_petsc = LAT.dense_numpy_2_petsc4py(A)
x0_petsc = p4pyPETSc.Vec().createWithArray(x0)
b1_petsc = p4pyPETSc.Vec().createWithArray(b1)
solver = LS.ChebyshevSemiIteration(A_petsc, alpha, beta, True)
solver.apply(b1_petsc, x0_petsc, 20)
expected = np.load(
os.path.join(self._scriptdir, 'import_modules/sol_10.npy'))
actual = x0_petsc
assert np.allclose(expected, actual.getArray())
def test_chebyshev_iteration_2(self):
''' Tests the pcd_shell operators produce correct output. '''
A = np.diag(1. / np.diag(self.quad_mass_matrix)).dot(
self.quad_mass_matrix)
n = self.quad_mass_matrix.shape[0]
alpha = 1. / 4
beta = 9. / 4
x0 = np.zeros(n)
b1 = np.zeros(n)
for i in range(0, n):
b1[i] = i
A_petsc = LAT.dense_numpy_2_petsc4py(A)
x0_petsc = p4pyPETSc.Vec().createWithArray(x0)
b1_petsc = p4pyPETSc.Vec().createWithArray(b1)
solver = LS.ChebyshevSemiIteration(A_petsc,
alpha,
beta,
save_iterations=True)
solver.apply(b1_petsc, x0_petsc, 20)
expected = np.load(
os.path.join(self._scriptdir, 'import_modules/sol_20_lst.npy'))
for i, item in enumerate(expected):
assert np.allclose(item, solver.iteration_results[i], 1e-12)
def create_petsc_vecs(matrix_A):
"""
Creates a right-hand-side and solution PETSc4Py vector for
testing ksp solves.
Parameters
----------
matrix_A: :class:`p4pyPETSc.Mat`
Global matrix object
Returns
-------
vec_lst: tuple
This is a list of :class:`pypyPETSc.Vec` where the first is
a vector of ones (usually to act as a RHS-vector) while the
second vector is a vector of zeros (usually to act as a
storage vector for the solution).
"""
b = p4pyPETSc.Vec().create()
x = p4pyPETSc.Vec().create()
b.createWithArray(np.ones(matrix_A.getSizes()[0][0]))
x.createWithArray(np.zeros(matrix_A.getSizes()[0][0]))
return (b, x)
