otorchmizer 1.0.0

A PyTorch-based library for nature-inspired meta-heuristic optimization

Otorchmizer: A PyTorch-Powered Nature-Inspired Optimizer

Welcome to Otorchmizer.

Did you ever reach a bottleneck in your computational experiments? Are you tired of waiting hours for meta-heuristic optimization runs? If yes, Otorchmizer is the real deal! This package provides an easy-to-go implementation of 91 meta-heuristic optimization algorithms — all powered by PyTorch tensors for GPU-accelerated performance. From populations to search spaces, from internal functions to external communication, we will foster all research related to optimizing stuff.

Otorchmizer is the modernized successor to Opytimizer, delivering up to 2,311× speedup by replacing NumPy with PyTorch.

Use Otorchmizer if you need a library or wish to:

• Create your optimization algorithm with automatic GPU support;
• Design or use pre-loaded optimization tasks at scale;
• Run the same code on CPU, single-GPU, or multi-GPU seamlessly;
• Leverage torch.compile and CUDA Graphs for maximum throughput;
• Mix-and-match different strategies to solve your problem;
• Because it is fun to optimize things — even faster.

Otorchmizer is compatible with: Python 3.10+ and PyTorch 2.0+.

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Package guidelines

1. The very first information you need is in the very next section.
2. Installing is also easy if you wish to read the code and bump yourself into, follow along.
3. Note that there might be some additional steps in order to use our solutions.
4. If there is a problem, please do not hesitate, call us.
5. Finally, we focus on minimization. Take that in mind when designing your problem.

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Citation

If you use Otorchmizer to fulfill any of your needs, please cite the original Opytimizer paper:

@misc{rosa2019opytimizer,
    title={Opytimizer: A Nature-Inspired Python Optimizer},
    author={Gustavo H. de Rosa, Douglas Rodrigues and João P. Papa},
    year={2019},
    eprint={1912.13002},
    archivePrefix={arXiv},
    primaryClass={cs.NE}
}

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Getting started: 60 seconds with Otorchmizer

First of all. We have examples. Yes, they are commented. Just browse to examples/, chose your subpackage, and follow the example. We have high-level examples for most tasks we could think of, including GPU acceleration, torch.compile, and multi-GPU population splitting.

Alternatively, if you wish to learn even more, please take a minute:

Otorchmizer is based on the following structure, and you should pay attention to its tree:

- otorchmizer
    - core
        - agent_view
        - block
        - device
        - function
        - node
        - optimizer
        - population
        - space
    - functions
        - constrained
        - multi_objective
    - math
        - distribution
        - general
        - hyper
        - random
    - optimizers
        - boolean
        - evolutionary
        - misc
        - population
        - science
        - social
        - swarm
    - spaces
        - boolean
        - graph
        - grid
        - hyper_complex
        - pareto
        - search
        - tree
    - utils
        - callback
        - constant
        - exception
        - history
        - logging
    - visualization
        - convergence
        - surface

Core

Core is the core. Essentially, it is the parent of everything. You should find parent classes defining the basis of our structure. They should provide variables and methods that will help to construct other modules. The key innovation is the Population class, which stores all agent data as contiguous PyTorch tensors (n_agents, n_variables, n_dimensions), enabling vectorized operations and GPU parallelism. Also featured here is the DeviceManager, which handles CPU/GPU/multi-GPU resolution, mixed-precision, and CUDA Graph capture.

Functions

Instead of using raw and straightforward functions, why not try this module? Compose high-level abstract functions or even new function-based ideas in order to solve your problems. Functions are auto-vectorized across the entire population via torch.vmap — you write a single-agent function, and we handle the batching.

Math

Just because we are computing stuff does not mean that we do not need math. Math is the mathematical package containing low-level math implementations. From random numbers to distribution generation, you can find your needs on this module — all backed by PyTorch tensors for device-agnostic computation.

Optimizers

This is why we are called Otorchmizer. This is the heart of heuristics, where you can find 91 meta-heuristic optimization techniques across 7 families — swarm intelligence, evolutionary algorithms, science-inspired methods, and more. Every algorithm uses batched tensor operations, meaning the same code runs on CPU and GPU without modification.

Spaces

One can see the space as the place that agents will update their positions and evaluate a fitness function. However, the newest approaches may consider a different type of space. Thinking about that, we are glad to support diverse space implementations.

Utils

This is a utility package. Common things shared across the application should be implemented here. It is better to implement once and use as you wish than re-implementing the same thing repeatedly.

Visualization

Everyone needs images and plots to help visualize what is happening, correct? This package will provide every visual-related method for you. Check a specific variable convergence, your fitness function convergence, plot benchmark function surfaces, and much more!

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Installation

We believe that everything has to be easy. Not tricky or daunting, Otorchmizer will be the one-to-go package that you will need, from the first installation to the daily tasks implementing needs. If you may just run the following under your most preferred Python environment (raw, conda, virtualenv, whatever):

pip install -e .

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Environment configuration

Note that sometimes, there is a need for additional implementation. If needed, from here, you will be the one to know all of its details.

Ubuntu

No specific additional commands are needed.

Windows

No specific additional commands are needed.

MacOS

No specific additional commands are needed.

GPU Support

For GPU acceleration, install PyTorch with CUDA support:

pip install torch --index-url https://download.pytorch.org/whl/cu121

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How-To-Use: Minimal Example

Take a look at a quick working example of Otorchmizer. Note that we are not passing many extra arguments nor additional information to the procedure. For more complex examples, please check our examples/ folder.

import torch

from otorchmizer import Otorchmizer
from otorchmizer.core import Function, Space
from otorchmizer.optimizers.swarm import PSO

def sphere(x):
    return (x ** 2).sum(dim=(-1, -2))

n_agents = 20
n_variables = 2
lower_bound = [-10, -10]
upper_bound = [10, 10]

space = Space(n_agents=n_agents, n_variables=n_variables,
              lower_bound=lower_bound, upper_bound=upper_bound)
space.build()

optimizer = PSO()
function = Function(sphere)

opt = Otorchmizer(space, optimizer, function)
opt.start(n_iterations=1000)

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GPU Usage

Running on GPU requires only a single parameter change — all algorithms, spaces, and functions work identically:

# Automatically uses GPU if available, otherwise falls back to CPU
space = Space(n_agents=1000, n_variables=100,
              lower_bound=-10.0, upper_bound=10.0,
              device="auto")
space.build()

For even more performance, enable torch.compile JIT acceleration:

optimizer = PSO()
optimizer.compile(space.population)
optimizer.torch_compile(mode="reduce-overhead")

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Why Otorchmizer over Opytimizer?

Otorchmizer is a drop-in modernization of Opytimizer. The same algorithms, the same API style, but with a fundamentally different computational engine:

	Opytimizer	Otorchmizer
Backend	NumPy	PyTorch
Agent storage	List[Agent] (Python objects)	Population tensor (n, v, d)
Update loop	for agent in agents: (Python)	Batched tensor ops (vectorized)
GPU support	❌ None	✅ CUDA, multi-GPU, CUDA Graphs
Mixed precision	❌ float64 only	✅ float16, bfloat16, float32, float64
JIT compilation	❌ None	✅ torch.compile
Algorithms	92	91 (3 specialized deferred)
CPU speedup	1× (baseline)	50–1,055×
GPU speedup	—	up to 2,311×

For a detailed migration guide, see docs/MIGRATION_GUIDE.md.

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Algorithms (91 total)

Family	Count	Algorithms
Swarm	33	ABC, ABO, AF, AIWPSO, BA, BOA, BWO, CS, CSA, EHO, FA, FFOA, FPA, FSO, GOA, JS, KH, MFO, MRFO, PIO, PSO, RPSO, SAVPSO, SBO, SCA, SFO, SOS, SSA, SSO, STOA, VPSO, WAOA, WOA
Evolutionary	14	BSA, DE, EP, ES, FOA, GA, GHS, GOGHS, HS, IHS, IWO, NGHS, RRA, SGHS
Misc	5	AOA, CEM, DOA, GS, HC
Population	11	AEO, AO, COA, EPO, GCO, GWO, HHO, OSA, PPA, PVS, RFO
Science	19	AIG, ASO, BH, CDO, EFO, EO, ESA, GSA, HGSO, LSA, MOA, MVO, SA, SMA, TEO, TWO, WCA, WDO, WEO
Social	6	BSO, CI, ISA, MVPA, QSA, SSD
Boolean	3	BMRFO, BPSO, UMDA

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Benchmarks

Results from 432 paired configurations across 3 backends (NumPy, PyTorch CPU, PyTorch GPU on an NVIDIA RTX 4070):

Metric	Value
Average CPU speedup	173×
Peak CPU speedup	1,055× (GA, 1000 agents, 100 dims)
Average GPU speedup	169×
Peak GPU speedup	2,311× (HC, 1000 agents, 100 dims)
Convergence quality	Parity with original

GPU execution time stays nearly constant (~0.03–0.08s) regardless of problem size, while NumPy grows linearly.

# Quick CPU-only benchmarks
python report/benchmarks/run_benchmarks.py --quick

# Full benchmark suite with GPU
python report/benchmarks/run_benchmarks.py --extended --gpu

# Generate all 13 visualization plots
python report/benchmarks/plot_results.py --input report/benchmarks/results_extended.json \
    --outdir report/benchmarks/plots_extended

See the full Migration Report for detailed analysis, tables, and all 13 benchmark plots.

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Testing

python -m pytest tests/ -v
# 197 passed

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Documentation

Resource	Description
Migration Guide	For existing Opytimizer users — API mapping, code examples, FAQ
Architecture Guide	Full design document covering Population, UpdateContext, DeviceManager
Migration Report	Detailed performance analysis with 13 benchmark plots
API Reference	Sphinx auto-generated docs (cd docs && make html)
Examples	Commented examples for core, optimizers, applications, GPU, and math

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Support

We know that we do our best, but it is inevitable to acknowledge that we make mistakes. If you ever need to report a bug, report a problem, talk to us, please do so! We will be available at our bests at this repository.

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License

Apache 2.0 — see LICENSE.