Variance of the Poisson distribution by its series

The series E(k^2) minus the squared series mean, truncated 15 standard deviations above a.

Usage

PoisVar(a)

Arguments

a

expected count, >= 0.

Value

list(variance).

References

Morin, D. J. (2016). Probability: For the Enthusiastic Beginner. Createspace. Eq (4.94).

Examples

PoisVar(3)$variance
#> [1] 3