On Jan 4, 2011, at 7:53 PM, Simon Slavin wrote: > > On 5 Jan 2011, at 12:20am, Igor Tandetnik wrote: > >> On 1/4/2011 7:11 PM, Simon Slavin wrote: >>> >>> >>> I bet I'm not the only one here old enough to remember FORTRAN and ALGOL >>> implementations with a 'RATIONAL' math type. It stored a numerator and >>> denominator for each number, and had absolutely no trouble with evaluating >>> >>> 1/4 + 1/6 + 1/12 + 1/3 >>> >>> precisely and accurately. >> >> Did it use arbitrary precision integer library? By asking it to >> evaluate, say, 1/2 + 1/3 + 1/4 + ... + 1/n, I can easily force the >> library to deal with numbers on the order of n!, which of course will >> quickly overflow any fixed-size registers. > > Back then I was programming on a PDP11, so both numerator and denominator > were probably 72 bits long. The routines always stored fractions in > normalised form, so ... <spreadsheet> ... you could multiply the first 18 > prime numbers together, up to 59, before it ran into problems. In practise, > of course, this almost never happened.
Not that I remember; ints were 16bits and longs were 32bits and floats were 32 and dfloats were 64bits on a PDP-11 Tom _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
