`get_dominated()` is very slow compared to other Python packages

[MLopez-Ibanez]

Hi,

You can find benchmarks of patatune's get_dominated() against similar functions in other Python packages here: https://multi-objective.github.io/moocore/python/#bench-ndom

Even in 2D, patatune is 10,000 times slower than moocore (despite using Numba). In my computer, moocore takes less than 0.1 seconds for processing 25k points in 4D, while patatune requires more than 10 seconds.

Please let me know if I am using patatune correctly. The implementation of the benchmark is available here: https://github.com/multi-objective/moocore/blob/main/python/benchmarks/bench_ndom.py

I have not benchmarked patatunes functions for computing hypervolume, generational distance, etc, but looking at their implementation, I expect that they will be at least 100 times slower than the equivalent functions in moocore.

Any suggestions or comments are welcome!

[rsreds]

Thanks for including patatune in your benchmarks. Very nice work.

I rerun the benchmarks and, while I got slightly better results, it still shows a 1000x faster time!

There is a lot to be optimized in our current implementation as it was never a strong focus.
The objective function that we run for most of CMS use cases are way slower than the domination check so the bottleneck wouldn't be there anyway.

However I did a very quick test and rough with hotswapping moocore and that would be straightforward enough with great improvements for almost no effort: https://github.com/cms-patatrack/patatune/tree/moocore.

The only issue I see is that moocore requires python 3.10 while the CMS software framework which is currently our principal use case still requires python 3.9 and would probably stay like this for a while.

I would be interested in using moocore for the core algorithms in patatune but that would require either rewriting the current implementation to "copy" the moocore one, or a backport of moocore.

[MLopez-Ibanez]

Python 3.9 reached end-of-life on 2025-10-31, so no security fixes will be available.

Nonetheless, I would be happy to modify moocore to work on Python 3.9 if somebody else figures out what needs to be modified. For example, moocore uses the match-statement, which is not available in Python 3.9, but it should be easy to work-around with if-else. Pull requests are welcome: https://github.com/multi-objective/moocore

Another alternative is to optionally use moocore:

[project]
name = "patatune"
requires-python = ">=3.9"
dependencies = [ "moocore; python_version >= '3.10'"]

Then use moocore conditionally:

import sys

if sys.version_info >= (3, 10):
    try:
        import moocore
    except ImportError:
        moocore = None
else:
    moocore = None

def get_dominated(x):
   if moocore is None: // current slow fallback
   else:
       moocore.is_nondominated()

This means that users can get faster code if they use Python 3.10 but their code keeps working as it is if they use Python 3.9. When you finally do the move to Python 3.10 (or higher), you just need to delete the slow fallback. This may also help you to detect any bugs in your or moocore implementations if users get different results with different Python versions. moocore has a much larger testsuite than patatune for these core functions: https://github.com/multi-objective/testsuite , we use fuzzing of inputs to actively find bugs, and no bugs are known at this moment, but of course bugs are always possible.

I honestly think any effort spent on the current patatune implementation or on copying or backporting moocore seems a waste to me and it would be better spent on improving other parts of patatune or moocore itself (which is not perfect).

[fwyzard]

The only issue I see is that moocore requires python 3.10 while the CMS software framework which is currently our principal use case still requires python 3.9 and would probably stay like this for a while.

The current development release of CMSSW, version 17.0.x, uses python 3.12.

However, all current production releases up to 16.1.x are stuck with python 3.9.

[rsreds]

Another alternative is to optionally use moocore:

Yes, in the simple implementation test branch I used something like that.

The current development release of CMSSW, version 17.0.x, uses python 3.12.

Considering this, I would probably opt for an optional dependency so it can be switched easily once CMSSW updates

[MLopez-Ibanez]

Let me know if you need anything in the moocore side. Suggestions for API, documentation changes or new functionality are welcome.