From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,69bb03cc695b330a X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-03-09 14:54:04 PST Path: supernews.google.com!sn-xit-03!supernews.com!nntp.cs.ubc.ca!newsfeed.stanford.edu!headwall.stanford.edu!unlnews.unl.edu!newsfeed.ksu.edu!nntp.ksu.edu!news.okstate.edu!dvdeug From: dvdeug@x8b4e53cd.dhcp.okstate.edu (David Starner) Newsgroups: comp.lang.ada Subject: Re: Large numbers (or is Ada the choice for me?) Date: 9 Mar 2001 20:44:18 GMT Organization: Oklahoma State University Message-ID: <98bfb2$a2g1@news.cis.okstate.edu> References: <98bbbg$jmf$1@nh.pace.co.uk> Reply-To: dstarner98@aasaa.ofe.org NNTP-Posting-Host: x8b4e531b.dhcp.okstate.edu User-Agent: slrn/0.9.6.3 (Linux) Xref: supernews.google.com comp.lang.ada:5588 Date: 2001-03-09T20:44:18+00:00 List-Id: On Fri, 9 Mar 2001 14:35:42 -0500, Marin David Condic wrote: >"Hans Georg Schaathun" wrote in message >news:slrn9ai9uk.iv9.georg@apal.ii.uib.no... >> I need a tool to solve large systems of linear equations, with no >> floating point operations (or any other approximations) allowed. >> Even though I am not a seasoned programmer, I think I'll have to >> write the tool myself. >> >This is a hopeless mission. Consider the instant you're row reduction >results in 1/3 - can you put that into a computer *without* an approximation >and still do math on it? The only issue then is how much accuracy is enough? Yes. Computers can handle fractions just fine with the appropriate package. I'm not sure it's feasible to have no approximations in a large system of linear equations, but it's possible. >A good place to start looking for Ada software is: http://www.adapower.org/ >A quick Google search with the words "Ada Linear Algebra" yielded: >http://www.cc.utah.edu/~nahaj/ada/math/linear.ads.html >http://www.masstech.com/mpdesc.htm > >See also: >http://lglwww.epfl.ch/Team/MW/mw_components.html > >As I recall Mats Weber had some Linear Algebra stuff in Ada... He also has a big number package. If efficency is key, I might look at the binding to gmp (http://www.ii.uib.no/~gisle/adagmp/). >easier than in most languages because you can create a package to house the >whole thing and use it just as if it was a native data type. Not easier than any other language with operator overloading and packages. (C++ would be significantly easier, as Ada won't let you make a type that "looks like" an integer.) >Nope. Nope and Not Applicable. You're either going to have to download >someone's large-number-package(s) or roll your own. I know of no general >purpose languages that are going to give you math on that big a scale right >out of the box. Common Lisp would give you the rationals and the big numbers out of the box. -- David Starner - dstarner98@aasaa.ofe.org Pointless website: http://dvdeug.dhis.org "I don't care if Bill personally has my name and reads my email and laughs at me. In fact, I'd be rather honored." - Joseph_Greg