Speaker: David R. Stoutemyer (UHM, ICS Department)

Title: A mathematical magic show: Demo and secrets of a prototype AskConstants website that can turn your floating-point results into the exact formulas that they want to be.”

Abstract: There are at least three existing websites that already do what the title promises:

https://isc.carma.newcastle.edu.au/

http://mrob.com/pub/ries/index.html

http://www.wolframalpha.com/

I will describe their techniques and some additional ones used in the AskConstants program. As a contest, if you email dstout at this university a floating-point constant or a float-free constant expression such as sqrt (3) / 2 + 3 * pi / 5, that I can convert to a float, then I will summarize how AskConstants and other such programs perform on that example. If you send a float, try to compute it using at least n-digit arithmetic where n is several more than the total number of digits, operators and functions in its float-free source. Good sources of ideas are calculus text definite integrals, algebraic numbers, values of special functions at rational arguments or at rational multiples of pi, constants from research literature and collections such as Steven Finch’s Encylopedia of Constants: