nessai 0.2.1

Nessai: Nested Sampling with Aritificial Intelligence

Nessai: Nested Sampling with Artificial Intelligence

nessai (/ˈnɛsi/): Nested Sampling with Aritificial Intelligence

nessai is a nested sampling algorithm for Bayesian Inference that incorporates normalisings flows. It is designed for applications where the Bayesian likelihood is computationally expensive.

Installation

nessai can be installed using pip:

$ pip install nessai

Installing via conda is not currently supported.

PyTorch

By default the version of PyTroch will not necessarily match the drivers on your system, to install a different version with the correct CUDA support see the PyTorch homepage for instructions: https://pytorch.org/.

Adding Bilby

This package requieres a fork of Bilby that includes the sampler, it can be installed by running (this requires pip):

$ pip install git+https://git.ligo.org/michael.williams/bilby.git@add-nessai-sampler#egg=bilby

Documentation

Documenation is available at: nessai.readthedocs.io

Contributing

Please see the guidelines here.

Acknowledgements

The core nested sampling code, model design and code for computing the posterior in nessai was based on cpnest with permission from the authors.

The normalising flows implemented in nessai are all either directly imported from nflows or heavily based on it.

Other code snippets that draw on existing code reference the source in their corresponding doc-strings.