1 System setup

1.1 Setting up a local fork of the bmm repository

Fork the bmm github repository. This will create a copy of the current development branch into your own github account
Clone your fork to your local machine
Create a new branch for your model, typically named feature/name-of-my-model

1.2 Package development via RStudio and devtools

The bmm package is setup as an RStudio project. Opening the bmm.Rproj file will open a new RStudio instance, which facilitates package development with a few commands from the devtools package. A great tutorial on package development can be found here. Below is a summary of the most important steps

Make sure you have the devtools package and a few others installed and loaded
```
install.packages(c("devtools", "roxygen2", "testthat", "knitr"))
library(devtools)
install_dev_deps()
```
To avoid having to load the devtools package every time, you can add the following code to your .Rprofile file
```
if (interactive()) {
  suppressMessages(require(devtools))
}
```
As noted here, you can create and open an .Rprofile file, if you don’t already have one with
```
use_devtools()
```
Load the current version of the bmm package based on your local files
```
load_all()  # or ctrl+shift+L
```
you can use this command whenever you make changes to the package code to see the changes in action. You should not call library(bmm) or source the files manually, as this will load the installed version of the package, not the one you are developing.
Make any changes to the package code that you need to make (elaborated in the next section)
Use check() to check the package for errors and warnings
```
check()
```
you should always ensure that check() produces no errors before submitting a pull request
Use document() to update the documentation
```
document()
```