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
Returns:	weights – psi(z) = (1 - (z/c)**2)**2 for |z| <= R psi(z) = 0 for |z| > R
Return type:	array