statsmodels.robust.norms.StudentT.psi#
- StudentT.psi(z)[source]#
The psi function of the StudentT norm
The analytic derivative of rho.
- Parameters:
- zarray_like
1d array
- Returns:
- psi
ndarray psi(z) = z * df / (df + (z / c)**2)
- psi
The psi function of the StudentT norm
The analytic derivative of rho.
1d array
ndarraypsi(z) = z * df / (df + (z / c)**2)