The goal of traj is to implement a three-step procedure in the spirit of Leffondree et al. (2004) to identify clusters of individual longitudinal trajectories. The procedure involves (1) computing a number of “measures of change”” capturing various features of the trajectories; (2) using a Principal Component Analysis based dimension reduction algorithm to select a subset of measures and (3) using the k-means clustering algorithm to identify clusters of trajectories.


You can install the development version of traj from GitHub with:

# install.packages("devtools")


See the vignette.