@cache_readonly
def resid_pearson(self):
    'Pearson standardize residual'
    std = np.sqrt(self.model.predict(self.params, which='var'))
    return (self.resid / std)
Pearson standardize residual
@cache_readonly
def resid_pearson(self):
    
    std = np.sqrt(self.model.predict(self.params, which='var'))
    return (self.resid / std)