def smooth(f, g, axis=None):
"""
Smooth a Function through simple moving average.
Parameters
----------
f : Function
The left-hand side of the smoothing kernel, that is the smoothed Function.
g : Function
The right-hand side of the smoothing kernel, that is the Function being smoothed.
axis : Dimension or list of Dimensions, optional
The Dimension along which the smoothing operation is performed. Defaults
to ``f``'s innermost Dimension.
Notes
-----
More info about simple moving average available at: ::
https://en.wikipedia.org/wiki/Moving_average#Simple_moving_average
"""
if g.is_Constant:
# Return a scaled version of the input if it's a Constant
f.data[:] = .9 * g.data
else:
if axis is None:
axis = g.dimensions[-1]
dv.Operator(dv.Eq(f, g.avg(dims=axis)), name='smoother')()
def norm(f, order=2):
"""
Compute the norm of a Function.
Parameters
----------
f : Function
Input Function.
order : int, optional
The order of the norm. Defaults to 2.
"""
kwargs = {}
if f.is_TimeFunction and f._time_buffering:
kwargs[f.time_dim.max_name] = f._time_size - 1
# Protect SparseFunctions from accessing duplicated (out-of-domain) data,
# otherwise we would eventually be summing more than expected
p, eqns = f.guard() if f.is_SparseFunction else (f, [])
with MPIReduction(f) as mr:
op = dv.Operator(eqns + [dv.Inc(mr.n[0], Abs(Pow(p, order)))],
name='norm%d' % order)
op.apply(**kwargs)
v = Pow(mr.v, 1 / order)
return np.float(v)
def sumall(f):
"""
Compute the sum of all Function data.
Parameters
----------
f : Function
Input Function.
"""
kwargs = {}
if f.is_TimeFunction and f._time_buffering:
kwargs[f.time_dim.max_name] = f._time_size - 1
# Protect SparseFunctions from accessing duplicated (out-of-domain) data,
# otherwise we would eventually be summing more than expected
p, eqns = f.guard() if f.is_SparseFunction else (f, [])
s = dv.types.Scalar(name='sum', dtype=f.dtype)
with MPIReduction(f) as mr:
op = dv.Operator([dv.Eq(s, 0.0)] + eqns +
[dv.Inc(s, p), dv.Eq(mr.n[0], s)],
name='sum')
op.apply(**kwargs)
return f.dtype(mr.v)
def first_touch(array):
"""Uses the Propagator low-level API to initialize the given array(in Devito types)
in the same pattern that would later be used to access it.
"""
exp_init = [Eq(array.indexed[array.indices], 0)]
op = devito.Operator(exp_init)
op.apply()
def assign(f, rhs=0, options=None, name='assign', **kwargs):
"""
Assign a list of RHSs to a list of Functions.
Parameters
----------
f : Function or list of Functions
The left-hand side of the assignment.
rhs : expr-like or list of expr-like, optional
The right-hand side of the assignment.
options : dict or list of dict, optional
Dictionary or list (of len(f)) of dictionaries containing optional arguments to
be passed to Eq.
name : str, optional
Name of the operator.
Examples
--------
>>> from devito import Grid, Function, assign
>>> grid = Grid(shape=(4, 4))
>>> f = Function(name='f', grid=grid, dtype=np.int32)
>>> g = Function(name='g', grid=grid, dtype=np.int32)
>>> h = Function(name='h', grid=grid, dtype=np.int32)
>>> functions = [f, g, h]
>>> scalars = [1, 2, 3]
>>> assign(functions, scalars)
>>> f.data
Data([[1, 1, 1, 1],
[1, 1, 1, 1],
[1, 1, 1, 1],
[1, 1, 1, 1]], dtype=int32)
>>> g.data
Data([[2, 2, 2, 2],
[2, 2, 2, 2],
[2, 2, 2, 2],
[2, 2, 2, 2]], dtype=int32)
>>> h.data
Data([[3, 3, 3, 3],
[3, 3, 3, 3],
[3, 3, 3, 3],
[3, 3, 3, 3]], dtype=int32)
"""
if not isinstance(rhs, list):
rhs = len(as_list(f)) * [
rhs,
]
eqs = []
if options:
for i, j, k in zip(as_list(f), rhs, options):
if k is not None:
eqs.append(dv.Eq(i, j, **k))
else:
eqs.append(dv.Eq(i, j))
else:
for i, j in zip(as_list(f), rhs):
eqs.append(dv.Eq(i, j))
dv.Operator(eqs, name=name, **kwargs)()
def assign(f, v=0):
"""
Assign a value to a Function.
Parameters
----------
f : Function
The left-hand side of the assignment.
v : scalar, optional
The right-hand side of the assignment.
"""
dv.Operator(dv.Eq(f, v), name='assign')()
def inner(f, g):
"""
Inner product of two Functions.
Parameters
----------
f : Function
First input operand
g : Function
Second input operand
Raises
------
ValueError
If the two input Functions are defined over different grids, or have
different dimensionality, or their dimension-wise sizes don't match.
If in input are two SparseFunctions and their coordinates don't match,
the exception is raised.
Notes
-----
The inner product is the sum of all dimension-wise products. For 1D Functions,
the inner product corresponds to the dot product.
"""
# Input check
if f.is_TimeFunction and f._time_buffering != g._time_buffering:
raise ValueError(
"Cannot compute `inner` between save/nosave TimeFunctions")
if f.shape != g.shape:
raise ValueError("`f` and `g` must have same shape")
if f._data is None or g._data is None:
raise ValueError("Uninitialized input")
if f.is_SparseFunction and not np.all(
f.coordinates_data == g.coordinates_data):
raise ValueError("Non-matching coordinates")
kwargs = {}
if f.is_TimeFunction and f._time_buffering:
kwargs[f.time_dim.max_name] = f._time_size - 1
# Protect SparseFunctions from accessing duplicated (out-of-domain) data,
# otherwise we would eventually be summing more than expected
rhs, eqns = f.guard(f * g) if f.is_SparseFunction else (f * g, [])
s = dv.types.Scalar(name='sum', dtype=f.dtype)
with MPIReduction(f, g) as mr:
op = dv.Operator([dv.Eq(s, 0.0)] + eqns +
[dv.Inc(s, rhs), dv.Eq(mr.n[0], s)],
name='inner')
op.apply(**kwargs)
return f.dtype(mr.v)
def sumall(f):
"""
Compute the sum of the values in a :class:`Function`.
Parameters
----------
f : Function
Input Function.
"""
kwargs = {}
if f.is_TimeFunction and f._time_buffering:
kwargs[f.time_dim.max_name] = f._time_size - 1
# Protect SparseFunctions from accessing duplicated (out-of-domain) data,
# otherwise we would eventually be summing more than expected
p, eqns = f.guard() if f.is_SparseFunction else (f, [])
with MPIReduction(f) as mr:
op = dv.Operator(eqns + [dv.Inc(mr.n[0], p)], name='sum')
op.apply(**kwargs)
return np.float(mr.v)
def first_touch(array):
"""
Uses an Operator to initialize the given array in the same pattern that
would later be used to access it.
"""
devito.Operator(Eq(array, 0.))()
