RE: Re: Could someone verify a long Pi calculation in Version 4 for me?

*To*: mathgroup at smc.vnet.net*Subject*: [mg36821] RE: [mg36806] Re: Could someone verify a long Pi calculation in Version 4 for me?*From*: "DrBob" <drbob at bigfoot.com>*Date*: Fri, 27 Sep 2002 04:15:23 -0400 (EDT)*Reply-to*: <drbob at bigfoot.com>*Sender*: owner-wri-mathgroup at wolfram.com

>>So would it take about the same amont of time for the complete printout of digits? Of course it would take a few additional seconds to format the output... I think it would take FAR more time for a complete printout, and might crash the Front End. I was thinking about the fact that I calculated all those digits and then threw them away. I could save them with Save or DumpSave, and read them in with Get the next time I wanted any of them, although the file would be close to 70 MB (if not more). I may do that, in fact -- I have plenty of disk space. The next step would be to somehow reuse the stored digits if I wanted MORE digits. But how? The Bailey-Borwein-Plouffe Pi algorithm is an avenue of attack, since it can calculate digits far from the decimal point, without calculating those in between. Unfortunately, it calculates hexadecimal digits in that way, not decimal digits. (That's true for the version I've seen, anyway.) Still, I could take the stored digits, convert to hexadecimal, add more hexadecimal digits with the B-B-P algorithm, and then convert back to decimal. In both conversions, I'd have to be very cognizant of how much precision I end up with, but that shouldn't be too difficult. It might go faster if I store hexadecimal digits, as well as decimal digits, to eliminate one of those conversions at each increase in the number of digits. The next step would be to set up an application that allowed anyone to ping for digits across the Internet, and would return them if they're stored. Hasn't someone already done that? It seems as if someone would have. Bobby Treat -----Original Message----- From: zeno [mailto:zeno1234 at mindspring.com] To: mathgroup at smc.vnet.net Subject: [mg36821] [mg36806] Re: Could someone verify a long Pi calculation in Version 4 for me? So would it take about the same amont of time for the complete printout of digits? Of course it would take a few additional seconds to format the output... Or does Mathematica take alot less time when it truncates the output? In article <amris4$576$1 at smc.vnet.net>, Tom Burton <tburton at brahea.com> wrote: > Hello, > > On 9/23/02 12:19 AM, in article ammfi5$lk7$1 at smc.vnet.net, "zeno" > <zeno1234 at mindspring.com> wrote: > > > Could you tell me the CPU you used and its speed etc...i am curious, > > thanks. It would be interesting to compare Version 4s Pi performance to > > other programs out there. > > I used one processor of a dual 1GH Mac and got the same answer with the > following speed: > > $Version > 4.2 for Mac OS X (June 4, 2002) > oldmax = $MaxPrecision > 6 > 1. 10 > $MaxPrecision = Infinity > Infinity > With[{n = 2^26}, Timing[ > pd = RealDigits[N[Pi, n + 1], 10, 20, > 19 - n]; ]] > {28794.1 Second, Null} > MaxMemoryUsed[] > 512055204 > pd > {{3, 3, 8, 6, 3, 2, 2, 0, 8, 9, 6, 2, 2, 3, > > 4, 0, 9, 8, 0, 3}, -67108844} > > Tom Burton