https://github.com/joeroe/era

R package for year-based time scales
https://github.com/joeroe/era

archaeology geology paleoclimate paleontology r r-package vctrs

Last synced: about 2 months ago
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R package for year-based time scales

• Host: GitHub
• URL: https://github.com/joeroe/era
• Owner: joeroe
• License: other
• Created: 2020-11-09T16:04:07.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2023-05-12T12:53:55.000Z (over 2 years ago)
• Last Synced: 2024-10-12T22:33:53.646Z (about 1 year ago)
• Topics: archaeology, geology, paleoclimate, paleontology, r, r-package, vctrs
• Language: R
• Homepage: https://era.joeroe.io
• Size: 794 KB
• Stars: 11
• Watchers: 3
• Forks: 0
• Open Issues: 9
• Metadata Files:
  • Readme: README.Rmd
  • Contributing: .github/CONTRIBUTING.md
  • License: LICENSE

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README

          
---

output: github_document

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "man/figures/README-",

  out.width = "100%"

)

```

# era 

[![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)

[![CRAN status](https://www.r-pkg.org/badges/version/era)](https://CRAN.R-project.org/package=era)

[![CRAN checks](https://badges.cranchecks.info/worst/era.svg)](https://cran.r-project.org/web/checks/check_results_era.html)

[![R-CMD-check](https://github.com/joeroe/era/actions/workflows/R-CMD-check.yaml/badge.svg)](https://github.com/joeroe/era/actions/workflows/R-CMD-check.yaml)

[![Test coverage](https://codecov.io/gh/joeroe/era/graph/badge.svg)](https://app.codecov.io/gh/joeroe/era)

**era** is an R package that provides a consistent representation of year-based time scales as a numeric vector with an associated *era* – the [yr class](https://era.joeroe.io/reference/yr.html).

It includes built-in [era definitions](https://era.joeroe.io/reference/eras.html) for many year numbering systems used in contemporary and historic calendars  (e.g. Common Era, Islamic 'Hijri' years); year-based time scales used in archaeology, astronomy, geology, and other palaeosciences (e.g.  Before Present, SI-prefixed *annus*); and support for [arbitrary user-defined eras](https://era.joeroe.io/reference/era.html). Years can converted from any one era to another using the generalised  transformation function [yr_transform()](https://era.joeroe.io/reference/yr_transform.html).

era's classes are based on [vctrs](https://vctrs.r-lib.org/), and come with methods for robust casting and coercion between years and other numeric types, type-stable arithmetic with years, and pretty-printing in tables.

## Installation

You can install the released version of era [from CRAN](https://cran.r-project.org/package=era) with:

```{r install, eval=FALSE}

install.packages("era")

```

Or the development version from [GitHub](https://github.com/joeroe/era) using the [remotes](https://remotes.r-lib.org/) package:

```{r install-dev, eval=FALSE}

# install.packages("remotes")

remotes::install_github("joeroe/era")

```

## Basic usage

`yr()` defines the era associated with a vector of years:

```{r eg-yr}

library(era)

x <- yr(c(9000, 8000, 7000), "cal BP")

x

```

Use `yr_transform()` to convert between eras:

```{r eg-transform}

yr_transform(x, "BCE")

```

Many common calendar systems and time scales are predefined (see `?eras()`) and can be referenced by their abbreviated labels.

Other eras can be defined using the `era()` function directly.

For further usage, see the [package introduction](https://era.joeroe.io/articles/era.html) (`vignette("era")`).