ViennaFit

A Python package for parameter optimization and calibration of ViennaPS process simulation models. ViennaFit automates the fitting of simulation parameters to match experimental data through various optimization algorithms and distance metrics.

Quick Example

import viennafit as fit
import viennaps as vps

# Create and initialize project
project = fit.Project("myOptimization", "./projects").initialize()
project.setInitialDomain(initialDomain)
project.setTargetLevelSet(targetLevelSet)

# Set up optimization
opt = fit.Optimization(project)
opt.setProcessSequence(processSequence)
opt.setVariableParameters({"param1": (0.1, 1.0), "param2": (10, 100)})
opt.setDistanceMetrics(primaryMetric="CCH")  # Chamfer distance

# Run optimization
opt.setName("run1")
opt.apply(numEvaluations=100)

Key Features

• Multiple Optimization Algorithms: dlib, Nevergrad, Ax/BoTorch (Bayesian optimization)
• Distance Metrics: Compare Area (CA), Chamfer (CCH), Sparse Field (CSF), Critical Dimensions (CCD), and more
• Sensitivity Analysis: Both local and global (Sobol) methods
• Multi-Domain Support: Optimize across multiple geometries simultaneously
• Custom Parameter Evaluation: Grid search and specific parameter combinations
• Incomplete Run Recovery: Load and analyze interrupted optimization runs
• Comprehensive Reporting: Convergence plots, parameter evolution, CSV/JSON outputs

Installation

Installing into a clean virtual environment is recommended.

Note: ViennaFit 2.0.0+ requires ViennaPS 4.0.0+. For ViennaPS 3.5.1, use ViennaFit 1.x.

# Clone the repository
git clone https://github.com/ViennaTools/ViennaFit
cd ViennaFit

# Install the package and dependencies
pip install .

Optional Dependencies

For Bayesian optimization (Ax/BoTorch):

pip install .[bayesian]

Requirements

Python: 3.10 or higher

Dependencies (installed automatically):

• ViennaPS >= 4.0.0
• dlib >= 19.24.6
• nevergrad >= 1.0.12
• NumPy >= 1.26
• cma >= 3.2.2
• SALib >= 1.5.1
• matplotlib >= 3.5
• pandas >= 1.5

Documentation

📚 Full Documentation: https://viennatools.github.io/ViennaFit/

• Examples - Working code examples

Quick Start

1. Create a project:

   project = fit.Project("myProject", "./projects").initialize()

2. Assign domains (initial geometry and target to match):

   project.setInitialDomain(initialDomain)
   project.setTargetLevelSet(targetLevelSet)

3. Define your process in a function that takes parameters:

   def processSequence(domain: vps.Domain, params: dict[str, float]):
       # Your simulation code using params
       return resultLevelSet

4. Run optimization:

   opt = fit.Optimization(project)
   opt.setProcessSequence(processSequence)
   opt.setVariableParameters({"param": (min, max)})
   opt.setDistanceMetrics(primaryMetric="CCH")
   opt.apply(numEvaluations=100)

Project Structure

Initialization creates the domains/ folder (and projectName-info.json). The remaining folders are created on demand when you run the corresponding study:

projectName/
├── projectName-info.json   # Project metadata
├── domains/
│   ├── initialDomain/      # Your starting geometry
│   ├── targetDomain/       # Goal to match
│   ├── annotations/        # Measurement data
│   └── optimalDomains/     # Best results
├── optimizationRuns/       # Results from optimizations
├── customEvaluations/      # Custom parameter evaluations
├── locSensStudies/         # Local sensitivity results
└── globSensStudies/        # Global sensitivity results

Citation

If you use ViennaFit in your research, please cite:

@software{viennafit,
  title = {ViennaFit},
  author = {Roman Kostal},
  year = {2025},
  url = {https://github.com/ViennaTools/ViennaFit}
}

A CITATION.cff file is also provided — use the "Cite this repository" button on GitHub.

License

Copyright © 2025 Institute for Microelectronics, TU Wien.

ViennaFit is released under the GNU General Public License v3. See LICENSE for details.

Support

• Documentation: https://viennatools.github.io/ViennaFit/
• Issues: https://github.com/ViennaTools/ViennaFit/issues
• Examples: See examples/ directory