  Methods for generating new distributions from old can be thought of as
techniques for simplifying integrals used in reverse. Hence integrating a
probability density function (pdf) by parts provides a new way of modifying
distributions; the resulting pdfs are integrals that sometimes require
computation as special functions. Summation by parts can be used similarly for
discrete distributions. The general methodology is given, with some examples of
distribution classes and of specific distributions, and fits to data.
