README.Rmd

---
output: github_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE, fig.path = "man/figures/README-")
set.seed(1)
```

# rater <img src="man/figures/rater.png" align="right" width="160" />

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**rater** provides tools for fitting and interrogating statistical models of repeated categorical rating data. The package provides a simple interface to fit a selection of these models, with arbitrary priors, using MCMC and optimisation provided by [Stan](https://mc-stan.org/). A selection of functions are also provided to plot parts of these models and extract key parameters. 

## Example usage:

```{r fit-demo, message = FALSE, warning = FALSE, results = "hide"}
library(rater)

fit <- rater(anesthesia, "dawid_skene") # sampling output suppressed
```

Get the posterior mean of the "pi" parameter.

```{r extract-demo}
point_estimate(fit, pars = "pi")
```

Plot the accuracy matrices of the raters.

```{r plot-demo}
plot(fit, pars = "raters")
```

## Installation

**rater** requires the **rstan** package to fit models. Detailed instructions to install **rstan** can be found [here](https://github.com/stan-dev/rstan/wiki/RStan-Getting-Started)

### CRAN 

**rater** is not *yet* on CRAN; when it is you will be able to install it with: 

```{r cran-installation, eval = FALSE}
#install.packages("rater")
```

### Development

To install the development version of **rater** from GitHub run:

```{r dev-installation, eval = FALSE}
# install.packages("remotes")
remotes::install_github("jeffreypullin/rater")
```

#### Installation notes:

- When installing from source, i.e. when installing the development version or installing from CRAN on Linux, the **Stan** models in the package will be compiled - this will lead to an install time of few minutes. Please be patient - this compilation means that **no** compilation is required when using the package

- During compilation many warnings may be displayed in the terminal; these 
are harmless but impossible to suppress.