def ildj_rule(incells, outcells, *, in_tree, out_tree, num_consts,
**_):
# First incell is a wrapped function because prim is a call primitive.
const_incells, incells = jax_util.split_list(incells, [num_consts])
if (all(outcell.top() for outcell in outcells)
and any(not incell.top() for incell in incells)):
flat_outvals = [outcell.val for outcell in outcells]
flat_outildjs = [outcell.ildj for outcell in outcells]
outvals = tree_util.tree_unflatten(out_tree, flat_outvals)
outildjs = tree_util.tree_unflatten(out_tree, flat_outildjs)
flat_invals = [
None if not incell.top() else incell.val
for incell in incells
]
invals = tree_util.tree_unflatten(in_tree, flat_invals)
try:
new_invals, new_ildjs = f_ildj(invals, outvals, outildjs)
except NonInvertibleError:
return const_incells + incells, outcells, None
# We need to flatten the output from `f_ildj` using
# `tree_util.tree_flatten` but if the user returns `None` (when
# inversion is not possible), JAX will remove `None`s from the flattened
# version and the number of `new_incells` will not match the old
# `incells`. We use the private `_replace_nones` feature in JAX to
# replace it with a sentinel that won't be removed when flattening.
none_ = object()
new_invals = tree_util._replace_nones(none_, new_invals) # pylint: disable=protected-access
new_ildjs = tree_util._replace_nones(none_, new_ildjs) # pylint: disable=protected-access
new_flat_invals = tree_util.tree_leaves(new_invals)
new_flat_ildjs = tree_util.tree_leaves(new_ildjs)
inslices = [
NDSlice.new(inval, ildj)
for inval, ildj in zip(new_flat_invals, new_flat_ildjs)
]
new_incells = []
for new_flat_inval, old_incell, inslice in zip(
new_flat_invals, incells, inslices):
if new_flat_inval is not none_:
new_incells.append(
InverseAndILDJ(old_incell.aval, [inslice]))
else:
new_incells.append(old_incell)
return const_incells + new_incells, outcells, None
elif (all(incell.top() for incell in incells)
and any(not outcell.top() for outcell in outcells)):
flat_invals = [incell.val for incell in incells]
invals = tree_util.tree_unflatten(in_tree, flat_invals)
outvals = self(*invals)
flat_outvals = tree_util.tree_leaves(outvals)
outcells = [
InverseAndILDJ.new(outval) for outval in flat_outvals
]
return const_incells + incells, outcells, None
return const_incells + incells, outcells, None
def apply_flat_fun_nokwargs(fun, io_tree, py_args):
in_tree_expected, out_tree = io_tree
args, in_tree = tree_flatten(py_args)
if in_tree != in_tree_expected:
raise TypeError("Expected {}, got {}".format(in_tree_expected, in_tree))
ans = fun(*args)
return tree_unflatten(out_tree, ans)
def apply_flat_fun(fun, io_tree, *py_args):
in_tree_expected, out_tree = io_tree
args, in_tree = tree_flatten((py_args, {}))
if in_tree != in_tree_expected:
raise TypeError(f"Expected {in_tree_expected}, got {in_tree}")
ans = fun(*args)
return tree_unflatten(out_tree, ans)
def dex_fun(*args, **kwargs):
args_flat, in_tree = tree_flatten((args, kwargs))
in_avals, in_tree_, keep_inputs = abstractify(args, kwargs)
assert in_tree == in_tree_
jaxpr, consts, out_tree = make_jaxpr(fun, in_tree, tuple(in_avals),
tuple(keep_inputs))
out_flat = dex_call_p.bind(*consts, *args_flat, jaxpr=jaxpr)
return tree_unflatten(out_tree, out_flat)
def flatten_fun_nokwargs2(in_tree, *args_flat):
py_args = tree_unflatten(in_tree, args_flat)
pair = yield py_args, {}
if not isinstance(pair, (list, tuple)) or len(pair) != 2:
raise TypeError("expected function with aux output to return a two-element "
f"tuple, but got type {type(pair)} with value {repr(pair)}")
ans, aux = pair
ans_flat, ans_tree = tree_flatten(ans)
aux_flat, aux_tree = tree_flatten(aux)
yield (ans_flat, aux_flat), (ans_tree, aux_tree)
def testKdePyTree(self):
@jax.jit
def evaluate_kde(kde, x):
return kde.evaluate(x)
dtype = np.float32
rng = jtu.rand_default(self.rng())
dataset = rng((3, 15), dtype)
x = rng((3, 12), dtype)
kde = lsp_stats.gaussian_kde(dataset)
leaves, treedef = tree_util.tree_flatten(kde)
kde2 = tree_util.tree_unflatten(treedef, leaves)
tree_util.tree_map(lambda a, b: self.assertAllClose(a, b), kde, kde2)
self.assertAllClose(evaluate_kde(kde, x), kde.evaluate(x))
def flatten_axes(name, treedef, axis_tree, *, kws=False, tupled_args=False):
# given an axis spec tree axis_tree (a pytree with integers and Nones at the
# leaves, i.e. the Nones are to be considered leaves) that is a tree prefix of
# the given treedef, build a complete axis spec tree with the same structure
# and return the flattened result
# TODO(mattjj,phawkins): improve this implementation
proxy = object()
dummy = tree_unflatten(treedef, [object()] * treedef.num_leaves)
axes = []
add_leaves = lambda i, x: axes.extend([i] * len(tree_flatten(x)[0]))
try:
tree_map(add_leaves, _replace_nones(proxy, axis_tree), dummy)
except ValueError:
if kws:
# if keyword arguments are included in the tree, we make adapt the error
# message only to be about the positional arguments
treedef, leaf = treedef_children(treedef)
assert treedef_is_leaf(leaf)
axis_tree, _ = axis_tree
hint = ""
if tupled_args:
hint += (
f" Note that {name} that are non-trivial pytrees should always be "
f"wrapped in a tuple representing the argument list.")
if len(treedef.children()) == 1:
try:
flatten_axes(name, treedef, (axis_tree, ))
except ValueError:
pass # That's not the issue.
else:
hint += (
f" In particular, you're passing in a single argument which "
f"means that {name} might need to be wrapped in "
f"a singleton tuple.")
raise ValueError(f"{name} specification must be a tree prefix of the "
f"corresponding value, got specification {axis_tree} "
f"for value tree {treedef}.{hint}") from None
axes = [None if a is proxy else a for a in axes]
assert len(axes) == treedef.num_leaves
return axes
def ravel_pytree(pytree):
"""Ravel (i.e. flatten) a pytree of arrays down to a 1D array.
Args:
pytree: a pytree of arrays and scalars to ravel.
Returns:
A pair where the first element is a 1D array representing the flattened and
concatenated leaf values, with dtype determined by promoting the dtypes of
leaf values, and the second element is a callable for unflattening a 1D
vector of the same length back to a pytree of of the same structure as the
input ``pytree``. If the input pytree is empty (i.e. has no leaves) then as
a convention a 1D empty array of dtype float32 is returned in the first
component of the output.
For details on dtype promotion, see
https://jax.readthedocs.io/en/latest/type_promotion.html.
"""
leaves, treedef = tree_flatten(pytree)
flat, unravel_list = _ravel_list(leaves)
unravel_pytree = lambda flat: tree_unflatten(treedef, unravel_list(flat))
return flat, unravel_pytree
def flatten_fun_nokwargs(in_tree, *args_flat):
py_args = tree_unflatten(in_tree, args_flat)
ans = yield py_args, {}
yield tree_flatten(ans)
def flatten_fun(in_tree, *args_flat): py_args, py_kwargs = tree_unflatten(in_tree, args_flat) ans = yield py_args, py_kwargs yield tree_flatten(ans)
def flatten_fun_for_vmap(in_tree, *args_flat): py_args, py_kwargs = tree_unflatten(in_tree, args_flat) ans = yield py_args, py_kwargs yield tree_flatten(ans, is_leaf=is_vmappable)
