Subsets of data from the National Household Travel Survey 2017. It includes personal trips, mobility, demographic, and household information. It is suitable for data visualization, data wrangling, joining datasets, exploratory data analysis, group comparisons, simple linear regression, categorical data analysis, and data ethics discussion in data science and statistics classes.

A constrained two-dimensional Delaunay triangulation package
  providing both triangulation and generation of voronoi mosaics of 
  irregular spaced data.
  Please note that most of the functions are now also covered in package
  interp, which is a re-implementation from scratch under a free license
  based on a different triangulation algorithm.

Data handling and estimation functions for animal movement
    estimation from archival or satellite tags. Helper functions are included
    for making image summaries binned by time interval from Markov Chain Monte Carlo
    simulations.

Implements triple-difference (DDD) estimators for both average
              treatment effects and event-study parameters. Methods include regression
              adjustment, inverse-probability weighting, and doubly-robust estimators,
              all of which rely on a conditional DDD parallel-trends assumption and
              allow covariate adjustment across multiple pre- and post-treatment
              periods. The methodology is detailed in Ortiz-Villavicencio and
              Sant'Anna (2025) <doi:10.48550/arXiv.2505.09942>.

Social Relation Model (SRM) analyses for single or multiple
    round-robin groups are performed. These analyses are either based on one
    manifest variable, one latent construct measured by two manifest variables,
    two manifest variables and their bivariate relations, or two latent
    constructs each measured by two manifest variables. Within-group t-tests
    for variance components and covariances are provided for single groups.
    For multiple groups two types of significance tests are provided:
    between-groups t-tests (as in SOREMO) and enhanced standard errors based on
    Lashley and Bond (1997) <DOI:10.1037/1082-989X.2.3.278>. Handling for missing values is provided.