Tools for Regression Using Pre-Computed Summary Statistics

Defines functions to describe regression models using only pre-computed summary statistics (i.e. means, variances, and covariances) in place of individual participant data. Possible models include linear models for linear combinations, products, and logical combinations of phenotypes. Implements methods presented in Wolf et al. (2021) Wolf et al. (2020) and Gasdaska et al. (2019) .