Parsing Expression Grammars in Rcpp (piton)
A wrapper around the ‘Parsing Expression Grammar Template Library’, a C++11 library for generating Parsing Expression Grammars, that makes it accessible within Rcpp. With this, developers can implement their own grammars and easily expose them in R packages.

Analysis with Profile Hidden Markov Models (aphid)
Designed for the development and application of hidden Markov models and profile HMMs for biological sequence analysis. Contains functions for multiple and pairwise sequence alignment, model construction and parameter optimization, file import/export, implementation of the forward, backward and Viterbi algorithms for conditional sequence probabilities, tree-based sequence weighting, and sequence simulation. Features a wide variety of potential applications including database searching, gene-finding and annotation, phylogenetic analysis and sequence classification.

Hierarchical Bayesian Design for Clinical Trials (hbdct)
Implements our hierarchical Bayesian design for randomized clinical trials.

Tidy Tools for Forecasting (sweep)
Tidies up the forecasting modeling and prediction work flow, extends the ‘broom’ package with ‘sw_tidy’, ‘sw_glance’, ‘sw_augment’, and ‘sw_tidy_decomp’ functions for various forecasting models, and enables converting ‘forecast’ objects to ‘tidy’ data frames with ‘sw_sweep’.

Generalized Random Forests (Beta) (grf)
A pluggable package for forest-based statistical estimation and inference. GRF currently provides methods for non-parametric least-squares regression, quantile regression, and treatment effect estimation (optionally using instrumental variables). This package is currently in beta, and we expect to make continual improvements to its performance and usability.