expectation.poisson_dist: Exact expectation for a Poisson distribution.
Description
Computes \(E[g(X)]\) using truncated summation over the support.
The summation is truncated at the \(1 - 10^{-12}\) quantile to
ensure negligible truncation error.
Usage
# S3 method for poisson_dist
expectation(x, g, ...)