statsmodels.robust.norms.TukeyBiweight.rho¶

TukeyBiweight.rho(z)[source]¶

The robust criterion function for Tukey’s biweight estimator

Parameters:¶

z : array_like¶

1d array

Returns:¶

rho – rho(z) = -(1 - (z/c)**2)**3 * c**2/6. for |z| <= R

rho(z) = 0 for |z| > R

Return type:¶

ndarray