pymc-devs/pymc

CheckParameterValues not replaced in inner graphs

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#6,697 opened on Apr 28, 2023

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Description

We include these rewrites when compiling logp graphs, but this won't replace inner logp graphs (e.g, inside Scan or not-inlined OpFromGraph)

https://github.com/pymc-devs/pymc/blob/371472dcf1c44f99a9ad4e7317606404b2a47a0e/pymc/pytensorf.py#L1142-L1144

The example in #6696 suffers from this. Sampling is quite faster when the rewrite is manually added

Contributor guide

Research direction
Inspect the rewrite logic in pytensorf.py around line 1142 to understand how graph rewrites are applied. Determine why inner graphs (e.g., inside Scan or not inlined OpFromGraph) are not processed and propose a method to traverse nested graphs to apply the CheckParameterValues rewrite. Consider performance implications and test with the example from issue #6696.
Tech stack
python
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Pythonbasic PyMC knowledge
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55