statsmodels.robust.norms.RobustNorm.psi#
- RobustNorm.psi(z)[source]#
Derivative of rho. Sometimes referred to as the influence function
Abstract method:
psi = rho’
- Parameters:
- zarray_like
1d array
- Returns:
ndarrayThe value of the psi function.
Derivative of rho. Sometimes referred to as the influence function
Abstract method:
psi = rho’
1d array
ndarrayThe value of the psi function.