# rater

**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 prior parameters, using MCMC and optimisation provided by Stan. A selection of functions are also provided to plot parts of these models and extract key parameters.

## Example usage:

```
library(rater)
fit <- rater(anesthesia, "dawid_skene") # Sampling output suppressed.
```

Get the posterior mean of the “pi” parameter.

`point_estimate(fit, "pi")`

```
## $pi
## [1] 0.37586040 0.40654649 0.14337154 0.07422156
```

Plot the accuracy matrices of the raters.

## Installation

**rater** requires the **rstan** package to fit models. Detailed instructions to install **rstan** can be found here

### CRAN

Install **rater** from CRAN with:

`install.packages("rater")`

### Development

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

```
# 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.