statsmodels.robust.norms.TukeyBiweight.weights

TukeyBiweight.weights(z)

Tukey’s biweight weighting function for the IRLS algorithm

The psi function scaled by z

Parameters:z (array-like) – 1d array Returns:weights – psi(z) = (1 - (z/c)**2)**2 for |z| <= R

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

Return type:array