Logistic Distribution

(continuous probab dist for equations)

Usage:

LogisticDist (x, μ, σ)

Definition:

 exp (-(x-μ)/σ) / (σ * (1 + exp (-(x-μ)/σ))^2)

Parameters:

μ = location       σ = scale

Required:

σ > 0

Moments:

Mean = Median = Mode = μ

variance = ((π * σ)^2)/3

kurtosis = 6/5

entropy = log(σ)+2

It resembles the normal distribution in shape but has heavier tails (higher kurtosis).  Its cumulative distribution function (cdf) is the logistic function.

See also logistic.