Overview

The bsitar package provides an interface for Bayesian implementation of the Super Imposition by Translation and Rotation (SITAR) growth model. The SITAR is a shape-invariant nonlinear mixed effect model that fits a natural cubic spline mean curve and aligns individual-specific growth curves to the underlying mean curve via a set of random effects: size, timing and intensity. The bsitar package package is a front-end to the R package brms which itself uses the Stan program to performing full Bayesian inference.

Installation

To install the latest release version from CRAN use

install.packages("bsitar")

The current developmental version can be installed from GitHub as:

if (!requireNamespace("remotes")) {
  install.packages("remotes")
}
remotes::install_github("Sandhu-SS/bsitar")

The brms package can be installed from the CRAN

install.packages("brms")

The latest developmental version of brms can be downloaded from GitHub as follows

remotes::install_github("paul-buerkner/brms")

Note that the brms, and hence the bsitar too, are based on Stan, and therefore a C++ compiler is required. The program Rtools (available on https://cran.r-project.org/bin/windows/Rtools/) comes with a C++ compiler for Windows. On Mac, you should install Xcode. For further instructions on how to get the compilers running, see the prerequisites section on https://github.com/stan-dev/rstan/wiki/RStan-Getting-Started.