(cwm)=
# Circulant Weighing Matrices #
<h1>A New Branch of The La Jolla Combinatorial Data Repository
</h1>

```{admonition} TL;DR
:class: warning
A data repository formerly made available via an SQL server is
repackaged as a Jupyter book, with code and data freely available.
```

```{admonition} Author
:class: tip
**Daniel M. Gordon**
{[gordon@ccrwest.org](mailto:gordon@ccrwest.org)}

IDA Center for Communications Research
4320 Westerra Court
San Diego, CA 92121 
USA
```


(abstract)=
## Abstract ##
> A weighing matrix $W = (w_{i,j})$
  is a square matrix of
  order $n$ and entries $w_{i,j}$ in $\{0, \pm 1\}$ such that
  $WW^T=kI_n$.  In his thesis, Strassler gave a table of
  existence results for circulant weighing matrices with $n \leq 200$
  and $k \leq 100$.  Since then, numerous papers have dealt with open
  cases in the table.
  
>  The author recently wrote a paper with K.T. Arasu and Yiran Zhang,
  resolving 12 more cases.  Rather than publishing a new version of
  the table in that paper, the results were added to the *La Jolla
  Combinatorics Repository*, an online database containing results on
  covering designs, difference sets and Steiner systems.  Here we give
  that data in the form of a Jupyter book, in the hopes of being more
  compatible with FAIR data management principles.



## Citation ##

```BibTeX
@misc{gordon2022cwm,
  title     = {Circulant Weighing Matrices,
  author    = {Gordon Daniel M.},
  year      = {2022},
  doi       = {10.5072/zenodo.1055443}
}
```

## About ##

:::{seealso}
The author's website, at <https://dmgordon.org/>, has data
repositories for difference sets, covering designs, circulant weighing
matrices and Steiner systems.
:::