leaps() performs an exhaustive search for the best subsets of the variables in x for predicting y in linear regression, using an efficient branch-and-bound algorithm. It is a compatibility wrapper for regsubsets does the same thing better.
Plots a table of models showing which variables are in each model. The models are ordered by the specified model selection statistic. This plot is particularly useful when there are more than ten or so models and the simple table produced by summary.regsubsets is too big to read.