# statsmodels.robust.norms.TukeyBiweight.weights¶

TukeyBiweight.weights(z)[source]

Tukey’s biweight weighting function for the IRLS algorithm

The psi function scaled by z

Parameters: z (array-like) – 1d array weights – psi(z) = (1 - (z/c)**2)**2 for |z| <= Rpsi(z) = 0 for |z| > R array