latrend: A Framework for Clustering Longitudinal Data

Clustering of longitudinal data is used to explore common trends among subjects over time. In this paper, we focus on cases where the sole repeated measurement of interest is numeric. Various R packages have been introduced throughout the years for identifying clusters of longitudinal patterns, summarizing the variability in trajectories between subjects in terms of one or more trends. We introduce the R package latrend as a framework for the unified application of methods for longitudinal clustering, enabling comparisons between methods with minimal coding. The package also serves as an interface to commonly used packages for clustering longitudinal data, including dtwclust, flexmix, kml, lcmm, mclust, mixAK, and mixtools. This enables researchers to easily compare different approaches, implementations, and method specifications. Furthermore, researchers can build upon the standard tools provided by the framework to quickly implement new cluster methods, enabling rapid prototyping.