pymc-devs / pymc-devs/pytensor

User facing split does not match numpy

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NumPy compatibility
Dominant language
Python
Stars
644
Forks
208
Avg merge
2d 14h
Merged PRs (30d)
16

Description

Description

Our implementation of Split expects the sizes of the subarrays (instead of the truncation points like numpy) and these must match to the full size of the input.

This is arguably a more sensible implementation as this is valid in numpy:

import numpy as np
np.split(np.zeros(10), [5, 2])

However users wanting to use split may be tripped by the fact it is different than the numpy one. We should offer a helper for the numpy one and keep ours internally. We can canonicalize to ours when we know all split sizes are non-decreasing.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the Split implementation and its current size-based behavior. Compare it with the numpy split behavior shown in the issue, then define the helper and canonicalization boundaries; done means users can request numpy-style split points while the existing internal representation remains supported.

Written by the indexing model from the issue text.

Assessment

Tech stack
numpy, python
Domain
data
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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