3.2.2.3.32.1.11. statsmodels.discrete.discrete_model.Poisson.jac

Poisson.jac(*args, **kwds)

jac is deprecated, use score_obs instead! Use score_obs method. jac will be removed in 0.7

Poisson model Jacobian of the log-likelihood for each observation

Parameters:

params : array-like

The parameters of the model

Returns:

score : ndarray (nobs, k_vars)

The score vector of the model evaluated at params

Notes

\[\frac{\partial\ln L_{i}}{\partial\beta}=\left(y_{i}-\lambda_{i}\right)x_{i}\]

for observations \(i=1,...,n\)

where the loglinear model is assumed

\[\ln\lambda_{i}=x_{i}\beta\]