statsmodels.robust.norms.TukeyBiweight.rho

method

TukeyBiweight.rho(z)[source]

The robust criterion function for Tukey’s biweight estimator

Parameters
zarray-like

1d array

Returns
rhoarray

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

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