Modify Data Using Externally Defined Modification Rules (dcmodify)
Data cleaning scripts typically contain a lot of ‘if this change that’ type of statements. Such statements are typically condensed expert knowledge. With this package, such ‘data modifying rules’ are taken out of the code and become in stead parameters to the work flow. This allows one to maintain, document, and reason about data modification rules separately from the workflow.

Stacked Area Plot (areaplot)
Produce a stacked area plot, or add polygons to an existing plot. The data can be a numeric vector, table, matrix, data frame, or a time-series object. Supports formula syntax and data can be plotted as proportions, so stacked areas equal 1.

Test for Equality of Covariance Matrices (covequal)
Computes p-values using the largest root test using an approximation to the null distribution by Johnstone (2008) <DOI:10.1214/08-AOS605>.

Survival Analysis using Copulas (Sunclarco)
Survival analysis for unbalanced clusters using Archimedean copulas (Prenen et al. (2016) <DOI:10.1111/rssb.12174>).

GeoJSON’ Topology Calculations and Operations (geoops)
Tools for doing calculations and manipulations on ‘GeoJSON’, a ‘geospatial’ data interchange format (<https://…/rfc7946> ). ‘GeoJSON’ is also valid ‘JSON’.

Weighting for Covariate Balance in Observational Studies (WeightIt)
Generates weights to form equivalent groups in observational studies by easing and extending the functionality of the R packages ‘twang’ (Ridgeway et al., 2017) <https://…/package=twang> for generalized boosted modeling, ‘CBPS’ (Fong, Ratkovic, & Imai, 2017) <https://…/package=CBPS> for covariate balancing propensity score weighting, ‘ebal’ (Hainbueller, 2014) <https://…/package=ebal> for entropy balancing, and ‘ATE’ (Haris & Chan, 2015) <https://…/package=ATE> for empirical balancing calibration weighting. Also allows for assessment of weights and checking of covariate balance by interfacing directly with ‘cobalt’ (Greifer, 2017) <https://…/package=cobalt>.