https://github.com/biboyd/pynucastro

a python library for nuclear astrophysics

https://github.com/biboyd/pynucastro

Repository

a python library for nuclear astrophysics

https://github.com/biboyd/pynucastro/blob/main/

# pynucastro

[![PyPI Version](https://img.shields.io/pypi/v/pynucastro)](https://pypi.org/project/pynucastro)
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[![DOI](http://joss.theoj.org/papers/10.21105/joss.00588/status.svg)](https://doi.org/10.21105/joss.00588)
[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1202434.svg)](https://doi.org/10.5281/zenodo.1202434)

[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/pynucastro/pynucastro/main?filepath=examples%2Fpynucastro-examples.ipynb)


![logo](logo/logo.png)

pynucastro is a python library for interactively creating and
exploring nuclear reaction networks.  It provides interfaces to
nuclear reaction rate databases, including the JINA Reaclib nuclear
reactions database.

The main features are:

  * Ability to create a reaction network based on a collection of rates, a set of nuclei,
    or an arbitrary filter applied to a library.

  * Interactive exploration of rates and networks in Jupyter notebooks.

  * Many different ways of visualizing a network.

  * An NSE solver to find the equilibrium abundance of a set of nuclei given a
    thermodynamic state.

  * Ability to write out python or C++ code needed to integrate the network.

  * Support for tabular weak rates.

  * Rate approximations and the derivation of reverse rates via detailed balance.

  * Easy access to nuclear properties, including T-dependent partition
    functions, spins, masses, etc.


## Documentation

Documentation for pynucastro is available here:

https://pynucastro.github.io/pynucastro/


## Examples

The following example reads in the ReacLib rate database and
gets the rate for C13(p,g)N14 and evaluates it at a
temperature of 1.e9 K and makes a plot of the T dependence:

```
In [1]: import pynucastro as pyna

In [2]: rl = pyna.ReacLibLibrary()

In [3]: c13pg = rl.get_rate_by_name("c13(p,g)n14")

In [4]: c13pg.eval(1.e9)
Out[4]: 3883.4778216250666

In [5]: fig = c13pg.plot()

In [6]: fig.savefig("c13pg.png")

```

The resulting figure is:
![](https://raw.githubusercontent.com/pynucastro/pynucastro/main/examples/c13pg.png)

An extensive demonstration of the capabilities of pynucastro is shown in this notebook:

[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/pynucastro/pynucastro/main?filepath=examples%2Fpynucastro-examples.ipynb)

[pynucastro-examples.ipynb](https://github.com/pynucastro/pynucastro/blob/main/examples/pynucastro-examples.ipynb)


We can also interactively explore a reaction network.  Here's an example of hot-CNO with breakout reactions:

[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/pynucastro/pynucastro/HEAD?labpath=examples%2Fhot-CNO-breakout-example.ipynb)

by increasing the temperature, you can see the transition from CNO to
hot-CNO (proton captures on C13 become faster than the beta decay) and
then the breakout of hot-CNO when the alpha capture on O14 becomes
faster than its decay.


## Installation

pynucastro is available on PyPI and can be installed via:
```
pip install pynucastro
```

Alternately, to install via source, you can do:
```
pip install .
```
for a systemwide install, or
```
pip install --user .
```
for a single-user install.  This will put the pynucastro modules and library in
the default location python searches for packages.


### Requirements

pynucastro is supported on Python 3.10 or later and the following libraries:

* `numpy`

* `sympy`

* `scipy`

* `matplotlib`

* `networkx`

* `ipywidgets`

* `numba`

To build the documentation or run the unit tests, `sphinx` and
`pytest` are additionally required along with some supporting
packages. See the included `requirements.txt` file for a list of these
packages and versions. To install the packages from the requirements
file, do:
```
pip install -r requirements.txt
```
Is important to stress out that all the dependencies should be
installed before `pynucastro`, otherwise the installation should be
repeated.


## Contributing

We welcome contributions from anyone, including posting issues or
submitting pull requests to the [pynucastro github][1]. For more details
on how to contribute to pynucastro, please see [CONTRIBUTING.md][2].

[1]: https://github.com/pynucastro/pynucastro
[2]: https://github.com/pynucastro/pynucastro/blob/main/CONTRIBUTING.md


### Core Developers

People who make a number of substantive contributions (new features,
bug fixes, etc.) will be named "core developers" of pynucastro.

Core developers will be recognized in the following ways:

  * invited to the group's slack team

  * listed in the User's Guide and website as a core developer

  * listed in the author list on the Zenodo DOI for the project
    (as given in the .zenodo.json file)

  * invited to co-author general code papers / proceedings describing
    pynucastro.  (Note: science papers that use pynucastro will always
    be left to the science paper lead author to determine authorship).

If a core developer is inactive for 3 years, we may reassess their
status as a core developer.


## Getting Help

We use our [Github Discussions][3] page for requesting help and
interacting with the community.

[3]: https://github.com/pynucastro/pynucastro/discussions

Owner

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