statsmodels.robust.norms.TukeyBiweight.psi¶
- TukeyBiweight.psi(z)[source]¶
The psi function for Tukey’s biweight estimator
The analytic derivative of rho
- Parameters:¶
- zarray_like
1d array
- Returns:¶
- psi
ndarray
psi(z) = z*(1 - (z/c)**2)**2 for |z| <= R
psi(z) = 0 for |z| > R
- psi
Last update:
Dec 23, 2024