> Numerical developers are not often in that habit, which is a shame. For certain! I don't know how anyone can do any serious numerical development without a

> Numerical developers are not often in that habit, which is a shame. For certain! I don't know how anyone can do any serious numerical development without a whole lot of test cases, including esoteric PhD-level numerical analysis stuff. I remember working with the IMSL libraries back in the 1970's and being in awe of the huge set of numerical tests they had in the test suite which gave them, from my point of view, an unbeatable lead in development. These were tests that were often about highly esoteric aspects of numerical stability in floating-point algorithms and were written by extremely well educated mathematicians with tons of numerical experience. For those who aren't greybeards IMSL (the International Mathematical Subroutine [now Statistical] Library) was one of the first uses of re-usable software in application programming. It started as decks of punch cards that you would put in a request for and the computing facility would punch a copy of the appropriate routines for you to include in your program deck.