statsmodels.discrete.discrete_model.Poisson.cdf¶

Poisson.cdf(X)[source]¶

Poisson model cumulative distribution function

Parameters:	X (array-like) – X is the linear predictor of the model. See notes.
Returns:
Return type:	The value of the Poisson CDF at each point.

Notes

The CDF is defined as

\[\exp\left(-\lambda\right)\sum_{i=0}^{y}\frac{\lambda^{i}}{i!}\]

where \(\lambda\) assumes the loglinear model. I.e.,

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

The parameter X is \(X\beta\) in the above formula.