stats
OLSInfluence.
resid_studentized_external
(cached attribute) studentized residuals using LOOO variance
this uses sigma from leave-one-out estimates
requires leave one out loop for observations
statsmodels.stats.outliers_influence.OLSInfluence.resid_std
statsmodels.stats.outliers_influence.OLSInfluence.resid_studentized_internal