statsmodels.discrete.discrete_model.Poisson.pdf¶
-
Poisson.
pdf
(X)[source]¶ Poisson model probability mass function
Parameters: X : array-like
X is the linear predictor of the model. See notes.
Returns: pdf : ndarray
The value of the Poisson probability mass function, PMF, for each point of X.
Notes
The PMF is defined as
\frac{e^{-\lambda_{i}}\lambda_{i}^{y_{i}}}{y_{i}!}
where \lambda assumes the loglinear model. I.e.,
\ln\lambda_{i}=x_{i}\beta
The parameter X is x_{i}\beta in the above formula.