chembayes 1.0.2

Experimental design and Bayesian optimization with Gaussian Processes and QMC sampling

ChemBayes

ChemBayes is a Python library designed to streamline experimental design (DoE) and Bayesian optimization for scientific and chemical research. It leverages Gaussian Processes to model complex response surfaces and efficiently identify optimal conditions.

🚀 Key Features

• Intelligent Sampling (QMC): Generate initial experimental designs using Halton sequences (Quasi-Monte Carlo) for optimal space-filling coverage. Supports integer, float, and categorical parameters.
• Automatic Preprocessing: Integrated handling of numeric variables (scaling) and categorical variables (one-hot encoding).
• Hyperparameter Tuning: Automated Gaussian Process parameter adjustment (Matern + WhiteKernel) using Leave‑One‑Out (LOO) cross‑validation and NLPD loss.
• Bayesian Optimization: Global maximum search using the Expected Improvement (EI) acquisition function. Supports both single‑objective and weighted multi‑objective optimization.
• Visual Diagnostics: Automated generation of model validation charts (true vs predicted with uncertainty), feature importance (permutation importance), and partial dependence plots (1D, 2D, and categorical bar charts).

📦 Installation

Option 1: Install from PyPI (recommended)

pip install chembayes

Option 2: Install from source (for development or latest version)

git clone https://github.com/jesusalmartin/chembayes.git
cd chembayes
pip install -e .

🛠️ Quick Start

1. Generating an Experimental Design (Sampling)

Define your search space with numeric and categorical parameters:

from chembayes import Sampler

# Create a sampler instance
sampler = Sampler()

# Add parameters
sampler.add_float('temperature', 20.0, 100.0)
sampler.add_int('time', 5, 60)
sampler.add_categoric('catalyst', ['Pd', 'Ni', 'Cu'])

# Generate 20 optimal experimental points
sampler.qmc_sampling(n_points=20)

# Get the sample as a DataFrame
df_experiments = sampler.get_df()

# Visualize the distribution of numeric parameters
sampler.plot()

You can also define parameters using a dictionary:

params = {
    'temperature': {'type': 'float', 'l_bound': 20.0, 'u_bound': 100.0},
    'time': {'type': 'int', 'l_bound': 5, 'u_bound': 60},
    'catalyst': {'type': 'categoric', 'categories': ['Pd', 'Ni', 'Cu']}
}

sampler.set_params(params)
sampler.qmc_sampling(20)

2. Bayesian Optimization

Once you have experimental data, find the optimal conditions:

Single Output Optimization

from chembayes import Optimizer

# Define input features and the target column
inputs = ['temperature', 'time', 'catalyst']
output = 'yield'

# Run the complete optimization pipeline
opt = Optimizer(
    data=df_data,
    inputs=inputs,
    output=output,
    n_tuning_trials=50,
    n_opt_trials=100
)

# Print the best parameters and predicted objective
opt.summary()

# Visualize model performance and feature importance
opt.true_vs_pred_plot()
opt.permutation_importance_plot()

# Generate partial dependence plots to understand the response surface
opt.partial_dependence_plot()

Weighted Multi‑Output Optimization

If you have multiple response variables and want to optimize a weighted combination:

# Define weights for each output (higher weight = more importance)
outputs = {
    'yield': 0.7,
    'selectivity': 0.2,
    'cost': 0.1
}

opt = Optimizer(
    data=df_data,
    inputs=inputs,
    output=outputs,
    n_tuning_trials=50,
    n_opt_trials=100
)

# Results automatically use the weighted objective
opt.summary()

📂 Project Structure

• src/chembayes/sampler.py: Tools for QMC sample generation.
• src/chembayes/optimizer.py: Bayesian optimization engine and Gaussian Processes.
• src/chembayes/__init__.py: Public API exposure.
• pyproject.toml: Modern package configuration and dependencies.

✉️ Contact & Contribution

Author: Jesus Alberto Martin del Campo
Email: [e-mail]
GitHub: jesusalmartin/chembayes

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