varian is a free, open source R package for variability analysis using Bayesian inference.

It provides a formula interface in R to define a multilevel model for a variable with repeated measures, in addition to standard multilevel features such as fixed effects and a random intercepts/slopes, the residual variance is a random variable by ID. The latent residual variance estimates are then used as predictors in a regression of another outcome.

Getting Started

At its core, varian uses Stan to estimate the models.

Prerequisites

R

R version 3.3.0 or later is required. You can download the latest version of R here:

http://www.r-project.org/

Tools

Stan and the varian package rely on being able to compile C++ code.

• For Windows, download and install Rtools at http://cran.r-project.org/bin/windows/Rtools/
• For Mac, make sure you have the latest version of Xcode installed. The installation instructions for rstan provide more details.
• For Linux, make sure you have a recent version of g++ or clang++.

RStan

Install the latest version of the rstan package (should happen automatically from CRAN now). That page also lists more detailed directions for getting the necessary tools installed.

Install varian

You can install:

• the latest stable release from CRAN

  install.packages("varian", dependencies = TRUE)

• the latest development version from github

  install.packages("devtools")
  devtools::install_github("JWiley/varian")

Learn about the theory

See our open access pre-print on the arXiv http://arxiv.org/abs/1411.2961.

More

• If you find a bug or have a feature request, please let us know on the issue tracker: https://github.com/JWiley/varian/issues.

• Have questions or need support? Email us at joshua.wiley@monash.edu and mention "varian" in the subject.