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# scikits.statsmodels.robust.norms.Hampel.weights

`Hampel.``weights`(z)

  Hampel weighting function for the IRLS algorithm

  The psi function scaled by z

  Parameters: | z : array-like 1d array
  Returns: | array : weights(z) = 1 for |z| <= a weights(z) = a/|z| for a < |z| <= b weights(z) = a*(c - |z|)/(|z|*(c-b)) for b < |z| <= c weights(z) = 0 for |z| > c

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