Nutpie fails to sample when RV changes shape following `with_data`
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bug
- Dominant language
- Python
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- 207
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- 28
- Avg merge
- 7d 21h
- Merged PRs (30d)
- 1
Description
import pymc as pm
import nutpie
with pm.Model() as model:
x = pm.Data('x', [0,1,2])
beta = pm.Normal('beta', mu=0, sigma=1)
y = pm.Normal("y", mu=beta * x, sigma=1) # fine if it's observed and we also change it's data
compiled_model = nutpie.compile_pymc_model(model)
compiled_model_set = compiled_model.with_data(x=[1,2])
nutpie.sample(compiled_model_set, chains=1)
# RuntimeError: All initialization points failed
# Caused by:
# Logp function returned error: ErrorCode(1)
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Research direction
Start by running the reproducer using nutpie.compile_pymc_model, compiled_model.with_data, and nutpie.sample with the changed x shape. Trace how with_data handles the shape change and how sampling initialization reports the log-probability error. Done means the shown model samples successfully after x changes from three to two values, with regression coverage for this case.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- machine-learning
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 65/100