# aion

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[![Project Status: Active – The project has reached a stable, usable state and is being actively developed.](https://www.repostatus.org/badges/latest/active.svg)](https://www.repostatus.org/#active) [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.8032278.svg)](https://doi.org/10.5281/zenodo.8032278) ## Overview Base R ships with a lot of functionality useful for time series, in particular in the **stats** package. However, these features are not adapted to most archaeological time series. These are indeed defined for a given calendar era, they can involve dates very far in the past and the sampling of the observation time is (in most cases) not constant. **aion** provides a system of classes and methods to represent and work with such time-series. Dates are represented as *rata die* (Reingold and Dershowitz 2018), i.e. the number of days since 01-01-01 (Gregorian), with negative values for earlier dates. This allows to represent dates independently of any calendar: it makes calculations and comparisons easier. Once a time series is created with **aion**, any calendar can be used for printing or plotting data (defaults to Gregorian Common Era; see `vignette("aion")`). **aion** does not provide tools for temporal modeling. Instead, it offers a simple API that can be used by other specialized packages. To cite aion in publications use: Frerebeau N, Roe J (2023). _aion: Archaeological Time Series_. Université Bordeaux Montaigne, Pessac, France. doi:10.5281/zenodo.8032278 , R package version 1.0.2, . Une entrée BibTeX pour les utilisateurs LaTeX est @Manual{, author = {Nicolas Frerebeau and Joe Roe}, title = {{aion: Archaeological Time Series}}, year = {2023}, organization = {Université Bordeaux Montaigne}, address = {Pessac, France}, note = {R package version 1.0.2}, url = {https://packages.tesselle.org/aion/}, doi = {10.5281/zenodo.8032278}, } This package is a part of the tesselle project . ## Installation You can install the released version of **aion** from [CRAN](https://CRAN.R-project.org) with: ``` r install.packages("aion") ``` And the development version from [GitHub](https://github.com/) with: ``` r # install.packages("remotes") remotes::install_github("tesselle/aion") ``` ## Usage ``` r ## Load package library(aion) ``` ``` r ## Set seed for reproductibility set.seed(12345) ## Create 6 time-series of 50 observations ## Sampled every two years starting from 2000 BP X <- series( object = matrix(rnorm(300), nrow = 50, ncol = 6), time = seq(from = 2000, by = -2, length.out = 50), calendar = calendar("BP") ) ## Plot plot(X) # Default calendar ``` ![](man/figures/README-time-series-1.png) ## Related Works - [**era**](https://github.com/joeroe/era): provides a consistent representation of year-based time scales as a numeric vector with an associated era. ## Contributing Please note that the **aion** project is released with a [Contributor Code of Conduct](https://www.tesselle.org/conduct.html). By contributing to this project, you agree to abide by its terms. ## References

Reingold, Edward M., and Nachum Dershowitz. 2018. *Calendrical Calculations: The Ultimate Edition*. 4th ed. Cambridge University Press. .