A set of tools for assessing covariate balance in observational studies numerically and graphically. The functions provide integration with the major R packages used for balancing covariates, including MatchIt, WeightIt, twang, CBPS, and many others, and support objects not made using these packages. They support binary, multi-category and continuous treatments, point and longitudinal treatments, and clustered and multiply imputed data.
The main functions of cobalt are the following:
bal.tab()
- generate tables of balance statistics before and after matching, weighting, or subclassification
bal.plot()
- generate plots to assess balance visually on one covariate at a time
love.plot()
- generate plots to summarize and report balance statistics
Other functions include get.w()
for extracting weights from objects produced by other packages, col_w_smd()
(and friends documented on the same page) for computing (weighted) balance statistics outside of bal.tab()
, bal.compute()
for computing scalar balance statistics efficiently, and splitfactor()
for splitting factor variables in a dataset into dummy variables.
cobalt has several vignettes, which can be accessed using vignette(package = "cobalt")
or visiting the website at https://ngreifer.github.io/cobalt/.
Maintainer: Noah Greifer noah.greifer@gmail.com (ORCID)
Useful links: