Hampel.psi(z)
[source]
The psi function for Hampel’s estimator
The analytic derivative of rho
Parameters: | z (array-like) – 1d array |
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Returns: |
psi – 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 |
Return type: | array |
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© 2006 Jonathan E. Taylor
Licensed under the 3-clause BSD License.
http://www.statsmodels.org/stable/generated/statsmodels.robust.norms.Hampel.psi.html