A class to represent Exponential Distribution
An interface method for cumulative distribution function (CDF). Optionally provides a cumulative probability of a value being between two values x1 and x2.
If called with 1 argument(x1) or if the value of second argument is empty string then returns CDF value for x1. If called with two arguments, x1 and x2 then returns a probability of a value being between x1 and x2.
Creates a new object for Exponential Distribution with the given rate parameter lambda
An interface method for probability distribution function (PDF). Returns PDF value for x.