Support non-numpy array backends by ColmTalbot · Pull Request #886 · bilby-dev/bilby

ColmTalbot · 2025-01-07T19:38:30Z

I've been working on this PR on and off for a few months, it isn't ready yet, but I wanted to share it in case other people had early opinions.

The goal is to make it easier to interface with models/samplers implemented in e.g., JAX, that support GPU/TPU acceleration and JIT compilation.

The general guiding principles are:

when possible maintain existing behaviour with numpy/builtin arguments
work introspectively so users don't need to specify the target backend, but use input types
write as little backend specific code as possible, mostly through using the array-api specification and scipy interoperability

The primary changes so far are:

making most priors backend independent, there are a few holdouts where the underlying scipy functionality isn't compatible yet
core likelihoods mostly work with data from any backend
GW likelihoods work with any backend supported by the source function
the GW detector objects don't work via introspection, they need to be manually set
GW geometry (currently in bilby_cython) is handled via multiple-dispatch and added back into bilby

Changed behaviour:

prior sampling/rescale shapes - related to Conserve rescale shape #863
some priors won't return floats on float input

Remaining issues:

Saving/loading nun-numpy arrays in result files may not work
I added some additional parameter conversions that I will remove
the bilby.gw.jaxstuff file should be removed and relevant functionality be moved elsewhere, it's currently just used for testing
the ROQ likelihood hasn't been ported
add more testing with JAX
translate some of the hyperparameter functionality, c.f., GWPopulation

ColmTalbot · 2026-01-23T15:48:31Z

This is now ready for review.
There are some things that won't work with JAX at the moment, e.g., various combinations of likelihood marginalization/acceleration.
I think we should accept this at the moment, for at least a bilby v3 alpha/beta release, and keep chipping away at the various subcases over time.

There are a lot of changes, but most of them are essentially np -> xp.
Some things required refactoring to avoid modifying slices of arrays as JAX doesn't like that.

Bilby can once again be installed without bilby.cython.
This should improve our general portability, but when bilby_cython is installed it will be used.

I've managed to keep test changes minimal:

I updated the joint prior test to make it more stringent (keys more randomly ordered).
I refactored some expensive prior initialization that was dramatically slowing things down.
I improved the logic for figuring out when ROQs are available to help my local testing.
Some mocks of numpy had to be updated.

mj-will

Some initial comments but I'll need to have another look.

ColmTalbot

Thanks for the initial comments @mj-will I'll take a pass at them ASAP.

GregoryAshton

Okay, I got through about 60% of the diff and I'm pausing here so will submit the questions so far.

GregoryAshton · 2026-02-19T14:28:25Z

-            _cdf[val >= self.minimum] = 1. - np.exp(-val[val >= self.minimum] / self.mu)
-        return _cdf
+        with np.errstate(divide="ignore"):
+            return -val / self.mu - xp.log(xp.asarray(self.mu)) + xp.log(val >= self.minimum)


Ah okay - are the bounds being implemented here? But, I don't see the upper bound being implemented.

I think this is carried over from the existing implementation.

ColmTalbot · 2026-05-14T22:13:10Z

Python 3.10 doesn't have support for a vmappable version of logsumexp through scipy leading to this job failing (https://github.com/bilby-dev/bilby/actions/runs/25883935510/job/76070707573?pr=886).

How do people feel about dropping support for Python 3.10 in Bilby 3? Numpy dropped support about a year ago.

…likelihood

This required making some changes to the tests for conditional dicts as I've changed the output types and the backend introspection doesn't work on dict_items for some reason

mj-will · 2026-05-28T08:05:53Z

i've not a proper look yet but one thought on using orng: I think ArrayRNG may be confusing so I'm considering changing it to something else (see sequince-dev/orng#9). Feel free to comment on the MR if you have thoughts.

No meaningful thoughts, I agree it's probably a positive change and I'm happy to update once it is available.

Once that's in, I can make a stable release and get in on conda if that would be useful.

I think we'll definitely want this once we have a release ready. Although, I think I've refactored things so that orng doesn't need to be a top-level dependency.

v0.1.0a6 and above now renames ArrayRNG to RandomGenerator

mj-will · 2026-06-08T10:34:00Z

@ColmTalbot orng 0.1.0 is now on conda forge: https://anaconda.org/channels/conda-forge/packages/orng/overview

GregoryAshton

I'm happy to approve and merge this with the idea to then ask all developers to test it and find the issues.

Co-authored-by: Michael J. Williams <michaeljw1@googlemail.com>

mj-will

Thanks again Colm for all your work on this!

Assuming the CI passes, I'm happy to approve this and we can continue to test it.

* Fixing #1047 Squeeze the output to one-dimension to fix incompatibility with numpy > 2.4 * Fix typo in interferometer.py to_pickle method (#1081) * REL: update changelog for 2.8.1 * MAINT: revert 4a92394 This reverts commit 4a92394. * BUG: apply from #886 for 1047 * REL: update changelog * Increase tolerance for log noise evidence comparison (#1087) closes #1086 * REL: add 1087 --------- Co-authored-by: Gregory Ashton <gregory.ashton@ligo.org> Co-authored-by: AlexandreGoettel <33029077+AlexandreGoettel@users.noreply.github.com> Co-authored-by: Matt Pitkin <m@ttpitk.in>

ColmTalbot added the enhancement New feature or request label Jan 7, 2025

ColmTalbot marked this pull request as draft January 7, 2025 19:38

ColmTalbot force-pushed the bilback branch from b902545 to af6881d Compare October 2, 2025 16:06

ColmTalbot force-pushed the bilback branch from 95020e5 to 0eeeaa5 Compare December 11, 2025 15:45

ColmTalbot force-pushed the bilback branch 2 times, most recently from ea348fa to 771a8a9 Compare January 22, 2026 17:00

ColmTalbot marked this pull request as ready for review January 23, 2026 15:24

ColmTalbot changed the title ~~DRAFT: Support non-numpy array backends~~ Support non-numpy array backends Jan 23, 2026

ColmTalbot added >100 lines refactoring to discuss To be discussed on an upcoming call labels Jan 23, 2026

ColmTalbot force-pushed the bilback branch from 2d28818 to 230f623 Compare January 23, 2026 16:51

mj-will added this to the 3.0.0 milestone Jan 27, 2026

mj-will reviewed Jan 27, 2026

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ColmTalbot commented Jan 28, 2026

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ColmTalbot mentioned this pull request Feb 17, 2026

FEAT: Add precessing spin transformation #1044

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GregoryAshton reviewed Feb 19, 2026

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mj-will removed the to discuss To be discussed on an upcoming call label May 14, 2026

ColmTalbot and others added 10 commits May 14, 2026 22:18

FEAT: enable backend switching for base gravitational-wave transient …

1e3f4af

…likelihood

FEAT: support multiband and relative binning likelihoods

cf5c611

FEAT: make more conversions backend agnostic

2bfc833

FEAT: use more normal conversions

d29b860

FEAT: move backend switching code to bilby

c5eb323

FEAT: make core prior backend agnostic

9bec666

FEAT: make non-numpy arrays serializable

0d9aba6

BUG: fix some array conversion methods

aea0ea8

DEV: some more prior agnosticism

8e61b7f

TEST: make all prior tests run

b658a02

This required making some changes to the tests for conditional dicts as I've changed the output types and the backend introspection doesn't work on dict_items for some reason

mj-will reviewed May 28, 2026

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Comment thread docs/array_api.rst Outdated

ColmTalbot added 4 commits June 24, 2026 09:27

Merge branch 'main' into bilback

f7cc216

Address review comments

8753446

TYPO: fix typo

c868541

BUG: fix torch symmetricloguniform

dd0e532

ColmTalbot requested review from a team and mj-will June 24, 2026 15:05

Merge branch 'main' into bilback

4e9c43f

GregoryAshton approved these changes Jun 25, 2026

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ColmTalbot enabled auto-merge June 25, 2026 15:58

mj-will reviewed Jun 25, 2026

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Comment thread bilby/core/prior/analytical.py Outdated

BUG: fix bug in beta log pdf

54970be

Co-authored-by: Michael J. Williams <michaeljw1@googlemail.com>

mj-will mentioned this pull request Jun 25, 2026

Standardizing prior behaviour outside the support #1102

Open

mj-will approved these changes Jun 25, 2026

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TYPO: remove excess whitespace

3dfc349

mj-will approved these changes Jun 25, 2026

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BUG: add type coercion for torch

101ca34

mj-will approved these changes Jun 26, 2026

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ColmTalbot added this pull request to the merge queue Jun 26, 2026

Merged via the queue into bilby-dev:main with commit 612c46b Jun 26, 2026
19 of 20 checks passed

ColmTalbot deleted the bilback branch June 26, 2026 07:16

ColmTalbot mentioned this pull request Jun 26, 2026

Fixing #1047 #1061

Closed

mj-will added a commit to mj-will/bilby that referenced this pull request Jun 29, 2026

BUG: apply from bilby-dev#886 for 1047

dcda70d

This was referenced Jun 29, 2026

REL: prepare 2.8.1 #1103

Merged

CI: update container dependencies #1105

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mj-will mentioned this pull request Jul 2, 2026

Rework return logic in SlabSpike prior rescale method #902

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