Here's my basis for the exponential, chi-squared, and gamma distribution design (forgive me for reiterating some points made by others):
Exponential is separate because both the CDF and inverse CDF have closed form computations. This provides better performance and higher accuracy than the iterative method approximation. Both exponential and chi-squared are separate from gamma to provide access only to the parameters specific to each distribution. In chi-squared case, extension could have easily been use but this would have exposed the alpha and beta properties in chi-squared. This would allow users to modify the properties in an uncontrolled fashion, possibly resulting in a disfunctional distribution. Thus, encapsulation was used to hide the gamma properties and only expose the relavent chi-squared properties. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
