def test_linearity_adjoint_F(self, shape, dtype, so):
"""
Test the linearity of the adjoint modeling operator by verifying:
a F^T(r) = F^T(a r)
"""
np.random.seed(0)
solver = acoustic_sa_setup(shape=shape, dtype=dtype, space_order=so)
src0 = solver.geometry.src
rec, _, _ = solver.forward(src0)
a = -1 + 2 * np.random.rand()
src1, _, _ = solver.adjoint(rec)
rec.data[:] = a * rec.data[:]
src2, _, _ = solver.adjoint(rec)
src1.data[:] *= a
# Check adjoint source wavefeild linearity
# Normalize by rms of rec2, to enable using abolute tolerance below
rms2 = np.sqrt(np.mean(src2.data**2))
diff = (src1.data - src2.data) / rms2
info("linearity adjoint F %s (so=%d) rms 1,2,diff; "
"%+16.10e %+16.10e %+16.10e" %
(shape, so, np.sqrt(np.mean(src1.data**2)), np.sqrt(np.mean(src2.data**2)),
np.sqrt(np.mean(diff**2))))
tol = 1.e-12
assert np.allclose(diff, 0.0, atol=tol)
def test_array_reduction(self, so, dim):
"""
Test generation of OpenMP reduction clauses involving Function's.
"""
grid = Grid(shape=(3, 3, 3))
d = grid.dimensions[dim]
f = Function(name='f',
shape=(3, ),
dimensions=(d, ),
grid=grid,
space_order=so)
u = TimeFunction(name='u', grid=grid)
op = Operator(Inc(f, u + 1),
opt=('openmp', {
'par-collapse-ncores': 1
}))
iterations = FindNodes(Iteration).visit(op)
assert "reduction(+:f[0:f_vec->size[0]])" in iterations[1].pragmas[
0].value
try:
op(time_M=1)
except:
# Older gcc <6.1 don't support reductions on array
info("Un-supported older gcc version for array reduction")
assert True
return
assert np.allclose(f.data, 18)
def basic_gradient_test(wave, space_order, v0, v, rec, F0, gradient, dm):
G = np.dot(mat2vec(gradient.data), dm.reshape(-1))
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = np.sqrt(v0**2 * v**2 /
((1 - H[i]) * v**2 + H[i] * v0**2))
vloc = Function(name='vloc',
grid=wave.model.grid,
space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(vp=vloc, dt=wave.model.critical_dt)[0]
# First order error Phi(m0+dm) - Phi(m0)
F_i = .5 * linalg.norm((d.data - rec.data).reshape(-1))**2
error1[i] = np.absolute(F_i - F0)
# Second order term r Phi(m0+dm) - Phi(m0) - <J(m0)^T \delta d, dm>
error2[i] = np.absolute(F_i - F0 - H[i] * G)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0): %s' % (p1))
info(r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>: %s' %
(p2))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def run(shape=(50, 50, 50),
spacing=(20.0, 20.0, 20.0),
tn=250.0,
autotune=False,
time_order=2,
space_order=4,
nbl=10,
kernel='centered',
full_run=False,
**kwargs):
solver = tti_setup(shape=shape,
spacing=spacing,
tn=tn,
space_order=space_order,
nbl=nbl,
kernel=kernel,
**kwargs)
info("Applying Forward")
rec, u, v, summary = solver.forward(autotune=autotune)
if not full_run:
return summary.gflopss, summary.oi, summary.timings, [rec, u, v]
info("Applying Adjoint")
solver.adjoint(rec, autotune=autotune)
return summary.gflopss, summary.oi, summary.timings, [rec, u, v]
def test_gradientJ(self, shape, kernel, space_order):
"""
This test ensures that the Jacobian computed with devito
satisfies the Taylor expansion property:
.. math::
F(m0 + h dm) = F(m0) + \O(h) \\
F(m0 + h dm) = F(m0) + J dm + \O(h^2) \\
with F the Forward modelling operator.
:param dimensions: size of the domain in all dimensions
in number of grid points
:param time_order: order of the time discretization scheme
:param space_order: order of the spacial discretization scheme
:return: assertion that the Taylor properties are satisfied
"""
spacing = tuple(15. for _ in shape)
wave = setup(shape=shape, spacing=spacing, dtype=np.float64,
kernel=kernel, space_order=space_order,
tn=1000., nbpml=10+space_order/2)
m0 = Function(name='m0', grid=wave.model.grid, space_order=space_order)
smooth(m0, wave.model.m)
dm = np.float64(wave.model.m.data - m0.data)
linrec = Receiver(name='rec', grid=wave.model.grid,
time_range=wave.receiver.time_range,
coordinates=wave.receiver.coordinates.data)
# Compute receiver data and full wavefield for the smooth velocity
rec, u0, _ = wave.forward(m=m0, save=False)
# Gradient: J dm
Jdm, _, _, _ = wave.born(dm, rec=linrec, m=m0)
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = m0.data + H[i] * dm
mloc = Function(name='mloc', grid=wave.model.m.grid, space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(m=mloc)[0]
delta_d = (d.data - rec.data).reshape(-1)
# First order error F(m0 + hdm) - F(m0)
error1[i] = np.linalg.norm(delta_d, 1)
# Second order term F(m0 + hdm) - F(m0) - J dm
error2[i] = np.linalg.norm(delta_d - H[i] * Jdm.data.reshape(-1), 1)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0) with slope: %s compared to 1' % (p1[0]))
info('2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>with slope:'
' %s comapred to 2' % (p2[0]))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def test_gradientJ(self, shape, kernel, space_order):
r"""
This test ensures that the Jacobian computed with devito
satisfies the Taylor expansion property:
.. math::
F(m0 + h dm) = F(m0) + \O(h) \\
F(m0 + h dm) = F(m0) + J dm + \O(h^2) \\
with F the Forward modelling operator.
"""
spacing = tuple(15. for _ in shape)
wave = setup(shape=shape, spacing=spacing, dtype=np.float64,
kernel=kernel, space_order=space_order,
tn=1000., nbpml=10+space_order/2)
m0 = Function(name='m0', grid=wave.model.grid, space_order=space_order)
smooth(m0, wave.model.m)
dm = np.float64(wave.model.m.data - m0.data)
linrec = Receiver(name='rec', grid=wave.model.grid,
time_range=wave.geometry.time_axis,
coordinates=wave.geometry.rec_positions)
# Compute receiver data and full wavefield for the smooth velocity
rec, u0, _ = wave.forward(m=m0, save=False)
# Gradient: J dm
Jdm, _, _, _ = wave.born(dm, rec=linrec, m=m0)
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = m0.data + H[i] * dm
mloc = Function(name='mloc', grid=wave.model.m.grid, space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(m=mloc)[0]
delta_d = (d.data - rec.data).reshape(-1)
# First order error F(m0 + hdm) - F(m0)
error1[i] = np.linalg.norm(delta_d, 1)
# Second order term F(m0 + hdm) - F(m0) - J dm
error2[i] = np.linalg.norm(delta_d - H[i] * Jdm.data.reshape(-1), 1)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0) with slope: %s compared to 1' % (p1[0]))
info(r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>with slope:'
' %s comapred to 2' % (p2[0]))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def check_norms(fn_norms, reference):
with open(fn_norms, 'r') as f:
norms = eval(f.read())
assert isinstance(norms, dict)
assert isinstance(reference, dict)
assert set(norms) == set(reference)
for k, v in norms.items():
norm = float(v)
info("norm(%s) = %f (expected = %f, delta = %f)"
% (k, norm, reference[k], abs(norm - reference[k])))
def test_gradientJ(self, dtype, space_order, kernel, shape, spacing, time_order,
setup_func):
"""
This test ensures that the Jacobian computed with devito
satisfies the Taylor expansion property:
.. math::
F(m0 + h dm) = F(m0) + \O(h) \\
F(m0 + h dm) = F(m0) + J dm + \O(h^2) \\
with F the Forward modelling operator.
"""
wave = setup_func(shape=shape, spacing=spacing, dtype=dtype,
kernel=kernel, space_order=space_order,
time_order=time_order, tn=1000., nbl=10+space_order/2)
v0 = Function(name='v0', grid=wave.model.grid, space_order=space_order)
smooth(v0, wave.model.vp)
v = wave.model.vp.data
dm = dtype(wave.model.vp.data**(-2) - v0.data**(-2))
# Compute receiver data and full wavefield for the smooth velocity
rec = wave.forward(vp=v0, save=False)[0]
# Gradient: J dm
Jdm = wave.jacobian(dm, vp=v0)[0]
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = np.sqrt(v0.data**2 * v**2 /
((1 - H[i]) * v**2 + H[i] * v0.data**2))
vloc = Function(name='vloc', grid=wave.model.grid, space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(vp=vloc)[0]
delta_d = (d.data - rec.data).reshape(-1)
# First order error F(m0 + hdm) - F(m0)
error1[i] = np.linalg.norm(delta_d, 1)
# Second order term F(m0 + hdm) - F(m0) - J dm
error2[i] = np.linalg.norm(delta_d - H[i] * Jdm.data.reshape(-1), 1)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0) with slope: %s compared to 1' % (p1[0]))
info(r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>with slope:'
' %s compared to 2' % (p2[0]))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def cli_run_jit_backdoor(problem, **kwargs):
"""`click` interface for the `run_jit_backdoor` mode in `benchmark.py`."""
# Preset shared parameters
kwargs['space_order'] = [12]
kwargs['time_order'] = [2]
kwargs['nbl'] = 10
kwargs['spacing'] = (20.0, 20.0, 20.0)
# Preset problem-specific parameters
if problem == 'tti':
kwargs['shape'] = (350, 350, 350)
kwargs['tn'] = 50 # End time of the simulation in ms
kwargs['dse'] = 'aggressive'
# Reference norms for the output fields
reference = {'rec': 66.417102, 'u': 30.707737, 'v': 30.707728}
elif problem == 'acoustic':
kwargs['shape'] = (492, 492, 492)
kwargs['tn'] = 100 # End time of the simulation in ms
kwargs['dse'] = 'advanced'
# Reference norms for the output fields
reference = {'rec': 184.526400, 'u': 151.545837}
else:
assert False
# Dummy values as they will be unused
kwargs['block_shape'] = []
kwargs['autotune'] = 'off'
retval = run_jit_backdoor(problem, **kwargs)
if retval is not None:
for i in retval:
if isinstance(i, DiscreteFunction):
v = norm(i)
info(
"norm(%s) = %f (expected = %f, delta = %f)" %
(i.name, v, reference[i.name], abs(v - reference[i.name])))
# Record DEVITO_ environment
env = [(k, v) for k, v in os.environ.items() if k.startswith('DEVITO_')]
content = "{%s}" % ", ".join("'%s': '%s'" % (k, v) for k, v in env)
with open('env.py', 'w') as f:
f.write(content)
def save_rec(rec, src_coords, path, nt_new):
comm = rec.grid.distributor.comm
rank = comm.Get_rank()
if rec.data.size != 0:
rec_save, coords = resample_shot(rec, nt_new)
info("From rank %s, shot record of size %s, number of rec locations %s" % (rank, rec_save.shape, coords.shape))
info("From rank %s, writing %s in rec, maximum value is %s" % (rank, rec_save.shape, np.max(rec_save)))
segy_write(rec_save,
[src_coords[0]],
[src_coords[-1]],
coords[:, 0],
coords[:, -1],
2.0, path + "_rank_%s.segy" % (rank),
sourceY=[src_coords[1]],
groupY=coords[:, 1])
def test_derivative_skew_symmetry(self, dtype, so):
"""
We ensure that the first derivatives constructed with calls like
f.dx(x0=x+0.5*x.spacing)
Are skew (anti) symmetric. See the notebook ssa_01_iso_implementation.ipynb
for more details.
"""
np.random.seed(0)
n = 101
d = 1.0
shape = (n, )
origin = (0., )
extent = (d * (n - 1), )
# Initialize Devito grid and Functions for input(f1,g1) and output(f2,g2)
grid1d = Grid(shape=shape, extent=extent, origin=origin, dtype=dtype)
x = grid1d.dimensions[0]
f1 = Function(name='f1', grid=grid1d, space_order=8)
f2 = Function(name='f2', grid=grid1d, space_order=8)
g1 = Function(name='g1', grid=grid1d, space_order=8)
g2 = Function(name='g2', grid=grid1d, space_order=8)
# Fill f1 and g1 with random values in [-1,+1]
f1.data[:] = -1 + 2 * np.random.rand(n, )
g1.data[:] = -1 + 2 * np.random.rand(n, )
# Equation defining: [f2 = forward 1/2 cell shift derivative applied to f1]
equation_f2 = Eq(f2, f1.dx(x0=x + 0.5 * x.spacing))
# Equation defining: [g2 = backward 1/2 cell shift derivative applied to g1]
equation_g2 = Eq(g2, g1.dx(x0=x - 0.5 * x.spacing))
# Define an Operator to implement these equations and execute
op = Operator([equation_f2, equation_g2])
op()
# Compute the dot products and the relative error
f1g2 = np.dot(f1.data, g2.data)
g1f2 = np.dot(g1.data, f2.data)
diff = (f1g2 + g1f2) / (f1g2 - g1f2)
info(
"skew symmetry (so=%d) -- f1g2, g1f2, diff; %+16.10e %+16.10e %+16.10e"
% (so, f1g2, g1f2, diff))
assert np.isclose(diff, 0., atol=1.e-12)
def test_adjoint_J(self, shape, dtype, so):
"""
Test the Jacobian of the forward modeling operator by verifying for
'random' dm, dr:
dr . J(dm) = J^T(dr) . dm
"""
np.random.seed(0)
solver = acoustic_ssa_setup(shape=shape, dtype=dtype, space_order=so)
src0 = solver.geometry.src
m0 = Function(name='m0', grid=solver.model.grid, space_order=so)
dm1 = Function(name='dm1', grid=solver.model.grid, space_order=so)
m0.data[:] = 1.5
# Model perturbation, box of random values centered on middle of model
dm1.data[:] = 0
size = 5
ns = 2 * size + 1
if len(shape) == 2:
nx2, nz2 = shape[0] // 2, shape[1] // 2
dm1.data[nx2-size:nx2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns)
else:
nx2, ny2, nz2 = shape[0] // 2, shape[1] // 2, shape[2] // 2
nx, ny, nz = shape
dm1.data[nx2-size:nx2+size, ny2-size:ny2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns, ns)
# Data perturbation
rec1 = solver.geometry.rec
nt, nr = rec1.data.shape
rec1.data[:] = np.random.rand(nt, nr)
# Linearized modeling
rec2, u0, _, _ = solver.jacobian_forward(dm1, src0, vp=m0, save=True)
dm2, _, _, _ = solver.jacobian_adjoint(rec1, u0, vp=m0)
sum_m = np.dot(dm1.data.reshape(-1), dm2.data.reshape(-1))
sum_d = np.dot(rec1.data.reshape(-1), rec2.data.reshape(-1))
diff = (sum_m - sum_d) / (sum_m + sum_d)
info(
"adjoint J %s (so=%d) sum_m, sum_d, diff; %16.10e %+16.10e %+16.10e"
% (shape, so, sum_m, sum_d, diff))
assert np.isclose(diff, 0., atol=1.e-11)
def test_linearity_forward_J(self, shape, dtype, so):
"""
Test the linearity of the forward Jacobian of the forward modeling operator
by verifying
a J(dm) = J(a dm)
"""
np.random.seed(0)
solver = acoustic_sa_setup(shape=shape, dtype=dtype, space_order=so)
src0 = solver.geometry.src
m0 = Function(name='m0', grid=solver.model.grid, space_order=so)
m1 = Function(name='m1', grid=solver.model.grid, space_order=so)
m0.data[:] = 1.5
# Model perturbation, box of random values centered on middle of model
m1.data[:] = 0
size = 5
ns = 2 * size + 1
if len(shape) == 2:
nx2, nz2 = shape[0]//2, shape[1]//2
m1.data[nx2-size:nx2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns)
else:
nx2, ny2, nz2 = shape[0]//2, shape[1]//2, shape[2]//2
nx, ny, nz = shape
m1.data[nx2-size:nx2+size, ny2-size:ny2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns, ns)
a = np.random.rand()
rec1, _, _, _ = solver.jacobian(m1, src0, vp=m0, save=True)
rec1.data[:] = a * rec1.data[:]
m1.data[:] = a * m1.data[:]
rec2, _, _, _ = solver.jacobian(m1, src0, vp=m0)
# Normalize by rms of rec2, to enable using abolute tolerance below
rms2 = np.sqrt(np.mean(rec2.data**2))
diff = (rec1.data - rec2.data) / rms2
info("linearity forward J %s (so=%d) rms 1,2,diff; "
"%+16.10e %+16.10e %+16.10e" %
(shape, so, np.sqrt(np.mean(rec1.data**2)), np.sqrt(np.mean(rec2.data**2)),
np.sqrt(np.mean(diff**2))))
tol = 1.e-12
assert np.allclose(diff, 0.0, atol=tol)
def test_array_reduction(self, so, dim):
"""
Test generation of OpenMP reduction clauses involving Function's.
"""
grid = Grid(shape=(3, 3, 3))
d = grid.dimensions[dim]
f = Function(name='f',
shape=(3, ),
dimensions=(d, ),
grid=grid,
space_order=so)
u = TimeFunction(name='u', grid=grid)
op = Operator(Inc(f, u + 1),
opt=('openmp', {
'par-collapse-ncores': 1
}))
iterations = FindNodes(Iteration).visit(op)
parallelized = iterations[dim + 1]
assert parallelized.pragmas
if parallelized is iterations[-1]:
# With the `f[z] += u[t0][x + 1][y + 1][z + 1] + 1` expr, the innermost
# `z` Iteration gets parallelized, nothing is collapsed, hence no
# reduction is required
assert "reduction" not in parallelized.pragmas[0].value
elif Ompizer._support_array_reduction(configuration['compiler']):
assert "reduction(+:f[0:f_vec->size[0]])" in parallelized.pragmas[
0].value
else:
# E.g. old GCC's
assert "atomic update" in str(iterations[-1])
try:
op(time_M=1)
except:
# Older gcc <6.1 don't support reductions on array
info("Un-supported older gcc version for array reduction")
assert True
return
assert np.allclose(f.data, 18)
def test_adjoint_F(self, shape, dtype, so):
"""
Test the forward modeling operator by verifying for random s, r:
r . F(s) = F^T(r) . s
"""
solver = acoustic_sa_setup(shape=shape, dtype=dtype, space_order=so)
src1 = solver.geometry.src
rec1 = solver.geometry.rec
rec2, _, _ = solver.forward(src1)
# flip sign of receiver data for adjoint to make it interesting
rec1.data[:] = rec2.data[:]
src2, _, _ = solver.adjoint(rec1)
sum_s = np.dot(src1.data.reshape(-1), src2.data.reshape(-1))
sum_r = np.dot(rec1.data.reshape(-1), rec2.data.reshape(-1))
diff = (sum_s - sum_r) / (sum_s + sum_r)
info("adjoint F %s (so=%d) sum_s, sum_r, diff; %+16.10e %+16.10e %+16.10e" %
(shape, so, sum_s, sum_r, diff))
assert np.isclose(diff, 0., atol=1.e-12)
def run_jit_backdoor(problem, **kwargs):
"""
A single run using the DEVITO_JIT_BACKDOOR to test kernel customization.
"""
configuration['develop-mode'] = False
setup = model_type[problem]['setup']
time_order = kwargs.pop('time_order')[0]
space_order = kwargs.pop('space_order')[0]
autotune = kwargs.pop('autotune')
info("Preparing simulation...")
solver = setup(space_order=space_order, time_order=time_order, **kwargs)
# Generate code (but do not JIT yet)
op = solver.op_fwd()
# Get the filename in the JIT cache
cfile = "%s.c" % str(op._compiler.get_jit_dir().joinpath(op._soname))
if not os.path.exists(cfile):
# First time we run this problem, let's generate and jit-compile code
op.cfunction
info("You may now edit the generated code in `%s`. "
"Then save the file, and re-run this benchmark." % cfile)
return
info("Running wave propagation Operator...")
@switchconfig(jit_backdoor=True)
def _run_jit_backdoor():
return solver.forward(autotune=autotune)
return _run_jit_backdoor()
def test_linearity_forward_F(self, shape, dtype, so):
"""
Test the linearity of the forward modeling operator by verifying:
a F(s) = F(a s)
"""
solver = acoustic_sa_setup(shape=shape, dtype=dtype, space_order=so)
src = solver.geometry.src
a = -1 + 2 * np.random.rand()
rec1, _, _ = solver.forward(src)
src.data[:] *= a
rec2, _, _ = solver.forward(src)
rec1.data[:] *= a
# Check receiver wavefeild linearity
# Normalize by rms of rec2, to enable using abolute tolerance below
rms2 = np.sqrt(np.mean(rec2.data**2))
diff = (rec1.data - rec2.data) / rms2
info("linearity forward F %s (so=%d) rms 1,2,diff; "
"%+16.10e %+16.10e %+16.10e" %
(shape, so, np.sqrt(np.mean(rec1.data**2)), np.sqrt(np.mean(rec2.data**2)),
np.sqrt(np.mean(diff**2))))
tol = 1.e-12
assert np.allclose(diff, 0.0, atol=tol)
def run(shape=(50, 50, 50), spacing=(20.0, 20.0, 20.0), tn=250.0,
autotune=False, space_order=4, nbl=10, preset='layers-tti',
kernel='centered', full_run=False, checkpointing=False, **kwargs):
solver = tti_setup(shape=shape, spacing=spacing, tn=tn, space_order=space_order,
nbl=nbl, kernel=kernel, preset=preset, **kwargs)
info("Applying Forward")
# Whether or not we save the whole time history. We only need the full wavefield
# with 'save=True' if we compute the gradient without checkpointing, if we use
# checkpointing, PyRevolve will take care of the time history
save = full_run and not checkpointing
# Define receiver geometry (spread across `x, y`` just below surface)
rec, u, v, summary = solver.forward(save=save, autotune=autotune)
if preset == 'constant':
# With a new m as Constant
v0 = Constant(name="v", value=2.0, dtype=np.float32)
solver.forward(save=save, vp=v0)
# With a new vp as a scalar value
solver.forward(save=save, vp=2.0)
if not full_run:
return summary.gflopss, summary.oi, summary.timings, [rec, u, v]
# Smooth velocity
initial_vp = Function(name='v0', grid=solver.model.grid, space_order=space_order)
smooth(initial_vp, solver.model.vp)
dm = np.float32(initial_vp.data**(-2) - solver.model.vp.data**(-2))
info("Applying Adjoint")
solver.adjoint(rec, autotune=autotune)
info("Applying Born")
solver.jacobian(dm, autotune=autotune)
info("Applying Gradient")
solver.jacobian_adjoint(rec, u, v, autotune=autotune, checkpointing=checkpointing)
return summary.gflopss, summary.oi, summary.timings, [rec, u, v]
def chain_contractions(A, B, C, D, E, F, optimize):
"""``AB + AC = D, DE = F``."""
op = Operator([Eq(D, A*B + A*C), Eq(F, D*E)], dle=optimize)
op.apply()
info('Executed `AB + AC = D, DE = F`')
def mat_mat_sum(A, B, C, D, optimize):
"""``AB + AC = D``."""
op = Operator(Eq(D, A*B + A*C), dle=optimize)
op.apply()
info('Executed `AB + AC = D`')
def mat_mat(A, B, C, optimize):
"""``AB = C``."""
op = Operator(Eq(C, A*B), dle=optimize)
op.apply()
info('Executed `AB = C`')
def transpose_mat_vec(A, x, b, optimize):
"""``A -> A^T, A^Tx = b``."""
i, j = A.indices
op = Operator([Eq(b, A.indexed[j, i]*x)], dle=optimize)
op.apply()
info('Executed `A^Tx = b`')
def mat_vec(A, x, b, optimize):
"""``Ax = b``."""
op = Operator(Eq(b, A*x), dle=optimize)
op.apply()
info('Executed `Ax = b`')
def test_gradientFWI(self, shape, kernel, space_order, checkpointing):
"""
This test ensures that the FWI gradient computed with devito
satisfies the Taylor expansion property:
.. math::
\Phi(m0 + h dm) = \Phi(m0) + \O(h) \\
\Phi(m0 + h dm) = \Phi(m0) + h \nabla \Phi(m0) + \O(h^2) \\
\Phi(m0) = .5* || F(m0 + h dm) - D ||_2^2
where
.. math::
\nabla \Phi(m0) = <J^T \delta d, dm> \\
\delta d = F(m0+ h dm) - D \\
with F the Forward modelling operator.
:param dimensions: size of the domain in all dimensions
in number of grid points
:param time_order: order of the time discretization scheme
:param space_order: order of the spacial discretization scheme
:return: assertion that the Taylor properties are satisfied
"""
spacing = tuple(10. for _ in shape)
wave = setup(shape=shape,
spacing=spacing,
dtype=np.float64,
kernel=kernel,
space_order=space_order,
nbpml=40)
m0 = Function(name='m0',
grid=wave.model.m.grid,
space_order=space_order)
m0.data[:] = smooth10(wave.model.m.data, wave.model.m.shape_domain)
dm = np.float32(wave.model.m.data - m0.data)
# Compute receiver data for the true velocity
rec, u, _ = wave.forward()
# Compute receiver data and full wavefield for the smooth velocity
rec0, u0, _ = wave.forward(m=m0, save=True)
# Objective function value
F0 = .5 * linalg.norm(rec0.data - rec.data)**2
# Gradient: <J^T \delta d, dm>
residual = Receiver(name='rec',
grid=wave.model.grid,
data=rec0.data - rec.data,
time_range=rec.time_range,
coordinates=rec0.coordinates.data)
gradient, _ = wave.gradient(residual,
u0,
m=m0,
checkpointing=checkpointing)
G = np.dot(gradient.data.reshape(-1), dm.reshape(-1))
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = m0.data + H[i] * dm
mloc = Function(name='mloc',
grid=wave.model.m.grid,
space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(m=mloc)[0]
# First order error Phi(m0+dm) - Phi(m0)
error1[i] = np.absolute(.5 * linalg.norm(d.data - rec.data)**2 -
F0)
# Second order term r Phi(m0+dm) - Phi(m0) - <J(m0)^T \delta d, dm>
error2[i] = np.absolute(.5 * linalg.norm(d.data - rec.data)**2 -
F0 - H[i] * G)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0): %s' % (p1))
info('2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>: %s'
% (p2))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def test_gradientFWI(self, shape, kernel, space_order, checkpointing):
r"""
This test ensures that the FWI gradient computed with devito
satisfies the Taylor expansion property:
.. math::
\Phi(m0 + h dm) = \Phi(m0) + \O(h) \\
\Phi(m0 + h dm) = \Phi(m0) + h \nabla \Phi(m0) + \O(h^2) \\
\Phi(m0) = .5* || F(m0 + h dm) - D ||_2^2
where
.. math::
\nabla \Phi(m0) = <J^T \delta d, dm> \\
\delta d = F(m0+ h dm) - D \\
with F the Forward modelling operator.
"""
spacing = tuple(10. for _ in shape)
wave = setup(shape=shape, spacing=spacing, dtype=np.float64,
kernel=kernel, space_order=space_order,
nbpml=40)
m0 = Function(name='m0', grid=wave.model.grid, space_order=space_order)
smooth(m0, wave.model.m)
dm = np.float32(wave.model.m.data[:] - m0.data[:])
# Compute receiver data for the true velocity
rec, u, _ = wave.forward()
# Compute receiver data and full wavefield for the smooth velocity
rec0, u0, _ = wave.forward(m=m0, save=True)
# Objective function value
F0 = .5*linalg.norm(rec0.data - rec.data)**2
# Gradient: <J^T \delta d, dm>
residual = Receiver(name='rec', grid=wave.model.grid, data=rec0.data - rec.data,
time_range=wave.geometry.time_axis,
coordinates=wave.geometry.rec_positions)
gradient, _ = wave.gradient(residual, u0, m=m0, checkpointing=checkpointing)
G = np.dot(gradient.data.reshape(-1), dm.reshape(-1))
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = m0.data + H[i] * dm
mloc = Function(name='mloc', grid=wave.model.m.grid, space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(m=mloc)[0]
# First order error Phi(m0+dm) - Phi(m0)
F_i = .5*linalg.norm((d.data - rec.data).reshape(-1))**2
error1[i] = np.absolute(F_i - F0)
# Second order term r Phi(m0+dm) - Phi(m0) - <J(m0)^T \delta d, dm>
error2[i] = np.absolute(F_i - F0 - H[i] * G)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0): %s' % (p1))
info(r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>: %s' % (p2))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def run(problem, **kwargs):
"""
A single run with a specific set of performance parameters.
"""
setup = model_type[problem]['setup']
options = {}
time_order = kwargs.pop('time_order')[0]
space_order = kwargs.pop('space_order')[0]
autotune = kwargs.pop('autotune')
options['autotune'] = autotune
block_shapes = as_tuple(kwargs.pop('block_shape'))
operator = kwargs.pop('operator', 'forward')
warmup = kwargs.pop('warmup')
# Should a specific block-shape be used? Useful if one wants to skip
# the autotuning pass as a good block-shape is already known
# Note: the following piece of code is horribly *hacky*, but it works for now
for i, block_shape in enumerate(block_shapes):
for n, level in enumerate(block_shape):
for d, s in zip(['x', 'y', 'z'], level):
options['%s%d_blk%d_size' % (d, i, n)] = s
solver = setup(space_order=space_order, time_order=time_order, **kwargs)
if warmup:
info("Performing warm-up run ...")
set_log_level('ERROR', comm=MPI.COMM_WORLD)
run_op(solver, operator, **options)
set_log_level('DEBUG', comm=MPI.COMM_WORLD)
info("DONE!")
retval = run_op(solver, operator, **options)
try:
rank = MPI.COMM_WORLD.rank
except AttributeError:
# MPI not available
rank = 0
dumpfile = kwargs.pop('dump_summary')
if dumpfile:
if configuration['profiling'] != 'advanced':
raise RuntimeError(
"Must set DEVITO_PROFILING=advanced (or, alternatively, "
"DEVITO_LOGGING=PERF) with --dump-summary")
if rank == 0:
with open(dumpfile, 'w') as f:
summary = retval[-1]
assert isinstance(summary, PerformanceSummary)
f.write(str(summary.globals_all))
dumpfile = kwargs.pop('dump_norms')
if dumpfile:
norms = [
"'%s': %f" % (i.name, norm(i)) for i in retval[:-1]
if isinstance(i, DiscreteFunction)
]
if rank == 0:
with open(dumpfile, 'w') as f:
f.write("{%s}" % ', '.join(norms))
return retval
def test_linearization_F(self, shape, dtype, so):
"""
Test the linearization of the forward modeling operator by verifying
for sequence of h decreasing that the error in the linearization E is
of second order.
E = 0.5 || F(m + h dm) - F(m) - h J(dm) ||^2
This is done by fitting a 1st order polynomial to the norms
"""
np.random.seed(0)
solver = acoustic_sa_setup(shape=shape, dtype=dtype, space_order=so)
src = solver.geometry.src
# Create Functions for models and perturbation
m0 = Function(name='m0', grid=solver.model.grid, space_order=so)
mm = Function(name='mm', grid=solver.model.grid, space_order=so)
dm = Function(name='dm', grid=solver.model.grid, space_order=so)
# Background model
m0.data[:] = 1.5
# Model perturbation, box of random values centered on middle of model
dm.data[:] = 0
size = 5
ns = 2 * size + 1
if len(shape) == 2:
nx2, nz2 = shape[0]//2, shape[1]//2
dm.data[nx2-size:nx2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns)
else:
nx2, ny2, nz2 = shape[0]//2, shape[1]//2, shape[2]//2
nx, ny, nz = shape
dm.data[nx2-size:nx2+size, ny2-size:ny2+size, nz2-size:nz2+size] = \
-1 + 2 * np.random.rand(ns, ns, ns)
# Compute F(m + dm)
rec0, u0, summary0 = solver.forward(src, vp=m0)
# Compute J(dm)
rec1, u1, du, summary1 = solver.jacobian(dm, src=src, vp=m0)
# Linearization test via polyfit (see devito/tests/test_gradient.py)
# Solve F(m + h dm) for sequence of decreasing h
dh = np.sqrt(2.0)
h = 0.1
nstep = 7
scale = np.empty(nstep)
norm1 = np.empty(nstep)
norm2 = np.empty(nstep)
for kstep in range(nstep):
h = h / dh
mm.data[:] = m0.data + h * dm.data
rec2, _, _ = solver.forward(src, vp=mm)
scale[kstep] = h
norm1[kstep] = 0.5 * np.linalg.norm(rec2.data - rec0.data)**2
norm2[kstep] = 0.5 * np.linalg.norm(rec2.data - rec0.data - h * rec1.data)**2
# Fit 1st order polynomials to the error sequences
# Assert the 1st order error has slope dh^2
# Assert the 2nd order error has slope dh^4
p1 = np.polyfit(np.log10(scale), np.log10(norm1), 1)
p2 = np.polyfit(np.log10(scale), np.log10(norm2), 1)
info("linearization F %s (so=%d) 1st (%.1f) = %.4f, 2nd (%.1f) = %.4f" %
(shape, so, dh**2, p1[0], dh**4, p2[0]))
# we only really care the 2nd order err is valid, not so much the 1st order error
assert np.isclose(p1[0], dh**2, rtol=0.25)
assert np.isclose(p2[0], dh**4, rtol=0.10)
def test_gradientFWI(self):
r"""
This test ensures that the FWI gradient computed with devito
satisfies the Taylor expansion property:
.. math::
\Phi(m0 + h dm) = \Phi(m0) + \O(h) \\
\Phi(m0 + h dm) = \Phi(m0) + h \nabla \Phi(m0) + \O(h^2) \\
\Phi(m0) = .5* || F(m0 + h dm) - D ||_2^2
where
.. math::
\nabla \Phi(m0) = <J^T \delta d, dm> \\
\delta d = F(m0+ h dm) - D \\
with F the Forward modelling operator.
"""
initial_model_filename = "overthrust_3D_initial_model_2D.h5"
true_model_filename = "overthrust_3D_true_model_2D.h5"
tn = 4000
dtype = np.float32
so = 6
nbl = 40
shots_container = "shots-iso"
shot_id = 10
##########
model0 = overthrust_model_iso(initial_model_filename,
datakey="m0",
dtype=dtype,
space_order=so,
nbl=nbl)
model_t = overthrust_model_iso(true_model_filename,
datakey="m",
dtype=dtype,
space_order=so,
nbl=nbl)
_, geometry, _ = initial_setup(initial_model_filename,
tn,
dtype,
so,
nbl,
datakey="m0")
# rec, source_location, old_dt = load_shot(shot_id,
# container=shots_container)
source_location = geometry.src_positions
solver_params = {
'h5_file': initial_model_filename,
'tn': tn,
'space_order': so,
'dtype': dtype,
'datakey': 'm0',
'nbl': nbl,
'origin': model0.origin,
'spacing': model0.spacing,
'shots_container': shots_container,
'src_coordinates': source_location
}
solver = overthrust_solver_iso(**solver_params)
true_solver_params = solver_params.copy()
true_solver_params['h5_file'] = true_model_filename
true_solver_params['datakey'] = "m"
solver_true = overthrust_solver_iso(**true_solver_params)
rec, _, _ = solver_true.forward()
v0 = mat2vec(clip_boundary_and_numpy(model0.vp.data, model0.nbl))
v_t = mat2vec(clip_boundary_and_numpy(model_t.vp.data, model_t.nbl))
dm = np.float64(v_t**(-2) - v0**(-2))
print("dm", np.linalg.norm(dm), dm.shape)
F0, gradient = fwi_gradient_shot(vec2mat(v0, model0.shape), shot_id,
solver_params, source_location)
G = np.dot(gradient.reshape(-1), dm.reshape(-1))
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
vloc = np.sqrt(v0**2 * v_t**2 /
((1 - H[i]) * v_t**2 + H[i] * v0**2))
m = Model(vp=vloc,
nbl=nbl,
space_order=so,
dtype=dtype,
shape=model0.shape,
origin=model0.origin,
spacing=model0.spacing,
bcs="damp")
# Data for the new model
d = solver.forward(vp=m.vp)[0]
# First order error Phi(m0+dm) - Phi(m0)
F_i = .5 * linalg.norm((d.data - rec.data).reshape(-1))**2
error1[i] = np.absolute(F_i - F0)
# Second order term r Phi(m0+dm) - Phi(m0) - <J(m0)^T \delta d, dm>
error2[i] = np.absolute(F_i - F0 - H[i] * G)
print(i, F0, F_i, H[i] * G)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0): %s' % (p1))
info(
r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>: %s'
% (p2))
print("Error 1:")
print(error1)
print("***")
print("Error 2:")
print(error2)
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def mat_vec(A, x, b, optimize):
"""``Ax = b``."""
op = Operator(Inc(b, A*x), dle=optimize)
op.apply()
info('Executed `Ax = b`')
def transpose_mat_vec(A, x, b, optimize):
"""``A -> A^T, A^Tx = b``."""
i, j = A.indices
op = Operator([Inc(b, A[j, i]*x)], dle=optimize)
op.apply()
info('Executed `A^Tx = b`')
def mat_mat(A, B, C, optimize):
"""``AB = C``."""
op = Operator(Inc(C, A*B), dle=optimize)
op.apply()
info('Executed `AB = C`')
def mat_mat_sum(A, B, C, D, optimize):
"""``AB + AC = D``."""
op = Operator(Inc(D, A*B + A*C), dle=optimize)
op.apply()
info('Executed `AB + AC = D`')
def chain_contractions(A, B, C, D, E, F, optimize):
"""``AB + AC = D, DE = F``."""
op = Operator([Inc(D, A*B + A*C), Inc(F, D*E)], dle=optimize)
op.apply()
info('Executed `AB + AC = D, DE = F`')
def test_gradientFWI(self, dtype, space_order, kernel, shape, ckp,
setup_func, time_order):
"""
This test ensures that the FWI gradient computed with devito
satisfies the Taylor expansion property:
.. math::
\Phi(m0 + h dm) = \Phi(m0) + \O(h) \\
\Phi(m0 + h dm) = \Phi(m0) + h \nabla \Phi(m0) + \O(h^2) \\
\Phi(m0) = .5* || F(m0 + h dm) - D ||_2^2
where
.. math::
\nabla \Phi(m0) = <J^T \delta d, dm> \\
\delta d = F(m0+ h dm) - D \\
with F the Forward modelling operator.
"""
spacing = tuple(10. for _ in shape)
wave = setup_func(shape=shape,
spacing=spacing,
dtype=dtype,
kernel=kernel,
tn=400.0,
space_order=space_order,
nbl=40,
time_order=time_order)
vel0 = Function(name='vel0',
grid=wave.model.grid,
space_order=space_order)
smooth(vel0, wave.model.vp)
v = wave.model.vp.data
dm = dtype(wave.model.vp.data**(-2) - vel0.data**(-2))
# Compute receiver data for the true velocity
rec = wave.forward()[0]
# Compute receiver data and full wavefield for the smooth velocity
if setup_func is tti_setup:
rec0, u0, v0, _ = wave.forward(vp=vel0, save=True)
else:
rec0, u0 = wave.forward(vp=vel0, save=True)[0:2]
# Objective function value
F0 = .5 * linalg.norm(rec0.data - rec.data)**2
# Gradient: <J^T \delta d, dm>
residual = Receiver(name='rec',
grid=wave.model.grid,
data=rec0.data - rec.data,
time_range=wave.geometry.time_axis,
coordinates=wave.geometry.rec_positions)
if setup_func is tti_setup:
gradient, _ = wave.jacobian_adjoint(residual,
u0,
v0,
vp=vel0,
checkpointing=ckp)
else:
gradient, _ = wave.jacobian_adjoint(residual,
u0,
vp=vel0,
checkpointing=ckp)
G = np.dot(gradient.data.reshape(-1), dm.reshape(-1))
# FWI Gradient test
H = [0.5, 0.25, .125, 0.0625, 0.0312, 0.015625, 0.0078125]
error1 = np.zeros(7)
error2 = np.zeros(7)
for i in range(0, 7):
# Add the perturbation to the model
def initializer(data):
data[:] = np.sqrt(vel0.data**2 * v**2 /
((1 - H[i]) * v**2 + H[i] * vel0.data**2))
vloc = Function(name='vloc',
grid=wave.model.grid,
space_order=space_order,
initializer=initializer)
# Data for the new model
d = wave.forward(vp=vloc)[0]
# First order error Phi(m0+dm) - Phi(m0)
F_i = .5 * linalg.norm((d.data - rec.data).reshape(-1))**2
error1[i] = np.absolute(F_i - F0)
# Second order term r Phi(m0+dm) - Phi(m0) - <J(m0)^T \delta d, dm>
error2[i] = np.absolute(F_i - F0 - H[i] * G)
# Test slope of the tests
p1 = np.polyfit(np.log10(H), np.log10(error1), 1)
p2 = np.polyfit(np.log10(H), np.log10(error2), 1)
info('1st order error, Phi(m0+dm)-Phi(m0): %s' % (p1))
info(
r'2nd order error, Phi(m0+dm)-Phi(m0) - <J(m0)^T \delta d, dm>: %s'
% (p2))
assert np.isclose(p1[0], 1.0, rtol=0.1)
assert np.isclose(p2[0], 2.0, rtol=0.1)
def test_analytic_comparison_2d(self, dtype, so):
"""
Wnsure that the farfield response from the propagator matches analytic reponse
in a wholespace.
"""
# Setup time / frequency
nt = 1001
dt = 0.1
tmin = 0.0
tmax = dt * (nt - 1)
fpeak = 0.090
t0w = 1.0 / fpeak
omega = 2.0 * np.pi * fpeak
# Model
space_order = 8
npad = 50
dx = 0.5
shape = (801, 801)
dtype = np.float64
qmin = 0.1
qmax = 100000
v0 = 1.5
init_damp = lambda fu, nbl: setup_w_over_q(fu, omega, qmin, qmax, nbl, sigma=0)
o = tuple([0]*len(shape))
spacing = tuple([dx]*len(shape))
model = Model(origin=o, shape=shape, vp=v0, b=1.0, spacing=spacing, nbl=npad,
space_order=space_order, bcs=init_damp)
# Source and reciver coordinates
src_coords = np.empty((1, 2), dtype=dtype)
rec_coords = np.empty((1, 2), dtype=dtype)
src_coords[0, :] = np.array(model.domain_size) * .5
rec_coords[0, :] = np.array(model.domain_size) * .5 + 60
geometry = AcquisitionGeometry(model, rec_coords, src_coords,
t0=0.0, tn=tmax, src_type='Ricker', f0=fpeak)
# Solver setup
solver = SaIsoAcousticWaveSolver(model, geometry, space_order=space_order)
# Numerical solution
recNum, uNum, _ = solver.forward()
# Analytic response
def analytic_response():
"""
Computes analytic solution of 2D acoustic wave-equation with Ricker wavelet
peak frequency fpeak, temporal padding 20x per the accuracy notebook:
examples/seismic/acoustic/accuracy.ipynb
u(r,t) = 1/(2 pi) sum[ -i pi H_0^2(k,r) q(w) e^{i w t} dw
where:
r = sqrt{(x_s - x_r)^2 + (z_s - z_r)^2}
w = 2 pi f
q(w) = Fourier transform of Ricker source wavelet
H_0^2(k,r) Hankel function of the second kind
k = w/v (wavenumber)
"""
sx, sz = src_coords[0, :]
rx, rz = rec_coords[0, :]
ntpad = 20 * (nt - 1) + 1
tmaxpad = dt * (ntpad - 1)
time_axis_pad = TimeAxis(start=tmin, stop=tmaxpad, step=dt)
srcpad = RickerSource(name='srcpad', grid=model.grid, f0=fpeak, npoint=1,
time_range=time_axis_pad, t0w=t0w)
nf = int(ntpad / 2 + 1)
df = 1.0 / tmaxpad
faxis = df * np.arange(nf)
# Take the Fourier transform of the source time-function
R = np.fft.fft(srcpad.wavelet[:])
R = R[0:nf]
nf = len(R)
# Compute the Hankel function and multiply by the source spectrum
U_a = np.zeros((nf), dtype=complex)
for a in range(1, nf - 1):
w = 2 * np.pi * faxis[a]
r = np.sqrt((rx - sx)**2 + (rz - sz)**2)
U_a[a] = -1j * np.pi * hankel2(0.0, w * r / v0) * R[a]
# Do inverse fft on 0:dt:T and you have analytical solution
U_t = 1.0/(2.0 * np.pi) * np.real(np.fft.ifft(U_a[:], ntpad))
# Note that the analytic solution is scaled by dx^2 to convert to pressure
return (np.real(U_t) * (dx**2)), srcpad
uAnaPad, srcpad = analytic_response()
uAna = uAnaPad[0:nt]
# Compute RMS and difference
diff = (recNum.data - uAna)
nrms = np.max(np.abs(recNum.data))
arms = np.max(np.abs(uAna))
drms = np.max(np.abs(diff))
info("Maximum absolute numerical,analytic,diff; %+12.6e %+12.6e %+12.6e" %
(nrms, arms, drms))
# This isnt a very strict tolerance ...
tol = 0.1
assert np.allclose(diff, 0.0, atol=tol)
