This module offers easy access to formulas for a few often-used 
distributions. For that, it uses the Math::Symbolic module which gives the 
user an opportunity to manufacture distributions to his liking.

The module can be used in two styles: It has a procedural interface which 
is demonstrated in the first half of the synopsis. But it also features a 
wholly different interface: It can modify the Math::Symbolic parser so 
that you can use the distributions right inside strings that will be 
parsed as Math::Symbolic trees. This is demonstrated for very simple cases 
in the second half of the synopsis.

All arguments in both interface styles are optional. Whichever expression 
is used instead of, for examle 'mean', is plugged into the formula for the 
distribution as a Math::Symbolic tree. Details on argument handling are 
explained below.

Please see the section on Export for details on how to choose the 
interface style you want to use.

WWW: http://search.cpan.org/dist/Math-SymbolicX-Statistics-Distributions/