Boltzmann (truncated Planck) Distribution

docs/tutorial:stats:discrete_boltzmann

Define $z = e^{- λ}$

M (t) = \frac{1 - e ^{N (t - λ)}}{1 - e ^{t - λ}} \frac{1 - e ^{- λ}}{1 - e ^{- λ N}}

Implementation: scipy.stats.boltzmann