statsmodels.discrete.discrete_model.Poisson.cdf¶

Poisson.cdf(X)[source]¶

Poisson model cumulative distribution function

Parameters:¶

Xarray_like

X is the linear predictor of the model. See notes.

Returns:¶

The value of the Poisson CDF at each point.

Notes

The CDF is defined as

$$\exp (-\lambda )\sum _{i=0}^y\frac{{\lambda }^i}{i!}$$

where $\lambda$ assumes the loglinear model. I.e.,

$$\ln {\lambda }_i=X\beta$$

The parameter X is $X\beta$ in the above formula.