LeastSquares.psi_deriv(z) [source]
The derivative of the least squares psi function.
| Returns: | psi_deriv – ones(z.shape) |
|---|---|
| Return type: | array |
Used to estimate the robust covariance matrix.
© 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.LeastSquares.psi_deriv.html