Goodman and Kruskall's gamma as an effect size. Yule's Q is a special case where coef1 and coef2 both have two coefficients, and is a symmetric effect size for the interaction of two experimental factors.
Column numbers in the design matrix for the first condition, in some meaningful order.
Corresponding column numbers for the second condition.
An object defining how to calculate an effect size.
effect_gamma_log2 is adapted to work with log2 scaled coefficients. This is almost certainly the version you want.