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:
- zarray_like
1d array
- Returns:
- weights
ndarray weights(z) = (1 - (z/c)**2)**2 for |z| <= c
weights(z) = 0 for |z| > c
- weights