Skip to content

Delay attaching ShapeFeature to logprob rewrites #8274

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ricardoV94 merged 1 commit into from
May 1, 2026
Merged

Delay attaching ShapeFeature to logprob rewrites #8274

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 12 additions & 5 deletions pymc/logprob/rewriting.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -58,7 +58,7 @@
from pytensor.tensor.random.rewriting import local_subtensor_rv_lift
from pytensor.tensor.rewriting.basic import register_canonicalize
from pytensor.tensor.rewriting.math import local_exp_over_1_plus_exp
from pytensor.tensor.rewriting.shape import ShapeFeature
from pytensor.tensor.rewriting.shape import ShapeOptimizer
from pytensor.tensor.subtensor import (
AdvancedIncSubtensor,
AdvancedIncSubtensor1,
Expand Down Expand Up @@ -149,6 +149,17 @@ def remove_DiracDelta(fgraph, node):
position=0,
)

# Attach ShapeFeature after `pre_lower_xtensor` (registered at position 0.1 in
# `pymc/dims/__init__.py`) so it never tracks shapes through xtensor wrappers,
# which would leak references to the underlying `RandomVariable`s into shape
# sub-graphs that no `lower_xtensor` round-trip can cancel.
logprob_rewrites_db.register(
"ShapeOpt",
ShapeOptimizer(),
"basic",
position=0.11,
)

# Introduce sigmoid. We do it before canonicalization so that useless mul are removed next
logprob_rewrites_db.register(
"local_exp_over_1_plus_exp",
Expand Down Expand Up @@ -245,15 +256,11 @@ def construct_ir_fgraph(
-------
A `FunctionGraph` of the measurable IR.
"""
# We add `ShapeFeature` because it will get rid of references to the old
# `RandomVariable`s that have been lifted; otherwise, it will be difficult
# to give good warnings when an unaccounted for `RandomVariable` is encountered
fgraph = FunctionGraph(
outputs=list(rv_values.keys()),
clone=True,
copy_orphans=False,
copy_inputs=False,
features=[ShapeFeature()],
)

# Replace valued RVs by ValuedVar Ops so that rewrites are aware of conditioning points
Expand Down
Loading