naras@stat.fsu.edu (B. Narasimhan) (07/02/89)
I recently saw a post about some multiple precsion package that a user found on his unix machine. The user then solicited input regarding other multiple precision packages. There is a truly outstanding multiple precision package for PC's and it is available absolutely free! It is UBASIC, a modified BASIC language interpreter written by a Japanese number theorist, Yuji Kida. A review of this software appears in "Computers and Mathematics", May/June 1989, by Prof. Walter Neumann. Features include some C-like syntax, exact arithmetic, real, integer, complex, on large numbers, etc. But nothing is more impressive than the bunch of number-theoretic routines. These include factorisation algorithms using some of the latest techniques, Quadratic sieve, Elliptic curve methods, and Adleman's primality testing routines. There is a specific version for 386 machines that takes advantage of 32-bit arithmetic. I was a heavy user of MAPLE on our sun until I discovered this. We needed a 60-digit number factored. MAPLE chugged along for a week and did not come up with the answer even after a week (our machine is not so heavily used), but UBASIC cracked it in 1 Hr and 44 minutes!!! Another useful feature is that UBASIC gives you the factors as it discovers them, so that you can stop and continue the rest of the factorisation when you want. Yesterday, UBASIC amazed me even more by cracking b^14+b^7+1, where b=2^32-5, a 134-digit number in about 2hrs. I have a copy of UBASIC, but I wonder if I would mess up Prof. Neumann's plans for distribution by volunteering to make it available to everyone. In any case, his e-mail address is TS2534@OHSTVMA.BITNET . I believe AMS is discussing setting up a bulletin board for this purpose. B. Narasimhan e-mail naras@stat.fsu.edu