Hampel.psi()
statsmodels.robust.norms.Hampel.psi
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Hampel.psi(z)
[source] -
The psi function for Hampel’s estimator
The analytic derivative of rho
Parameters: z : array-like
1d array
Returns: psi : array
psi(z) = z for |z| <= a
psi(z) = a*sign(z) for a < |z| <= b
psi(z) = a*sign(z)*(c - |z|)/(c-b) for b < |z| <= c
psi(z) = 0 for |z| > c
© 2009–2012 Statsmodels Developers
© 2006–2008 Scipy Developers
© 2006 Jonathan E. Taylor
Licensed under the 3-clause BSD License.
http://www.statsmodels.org/stable/generated/statsmodels.robust.norms.Hampel.psi.html