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|iminuit|

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iminuit is a Jupyter-friendly Python interface for the Minuit2 C++ library maintained by CERN's ROOT team.

It can be used as a general robust function minimisation method, but is most commonly used for likelihood fits of models to data, and to get model parameter error estimates from likelihood profile analysis.

• Supported CPython versions: 3.6+
• Supported PyPy versions: 3.6
• Supported platforms: Linux, OSX and Windows.

• PyPI: https://pypi.org/project/iminuit
• Documentation: http://iminuit.readthedocs.org
• Source: https://github.com/scikit-hep/iminuit
• Gitter: https://gitter.im/Scikit-HEP/community
• License: MINUIT2 is LGPL and iminuit is MIT
• Citation: https://doi.org/10.5281/zenodo.3949207

In a nutshell

.. code-block:: python

from iminuit import Minuit

def fcn(x, y, z):
    return (x - 2) ** 2 + (y - 3) ** 2 + (z - 4) ** 2

fcn.errordef = Minuit.LEAST_SQUARES

m = Minuit(fcn, x=0, y=0, z=0)

m.migrad()  # run optimiser
print(m.values)  # x: 2, y: 3, z: 4

m.hesse()   # run covariance estimator
print(m.errors)  # x: 1, y: 1, z: 1

Versions

The current 2.x series has introduced breaking interfaces changes with respect to the 1.x series.

All interface changes are documented in the changelog_ with recommendations how to upgrade. To keep existing scripts running, pin your major iminuit version to <2, i.e. pip install 'iminuit<2' installs the 1.x series.

.. _changelog: https://iminuit.readthedocs.io/en/stable/changelog.html