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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit Date: Fri, 18 Apr 2008 06:30:34 +0200 From: Gautier User-Agent: Thunderbird 2.0.0.12 (Windows/20080213) MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Symmetric matrices only! References: <2dfded9f-aa30-4b25-ba2b-6e0d7f6f0fab@a1g2000hsb.googlegroups.com> In-Reply-To: <2dfded9f-aa30-4b25-ba2b-6e0d7f6f0fab@a1g2000hsb.googlegroups.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit NNTP-Posting-Host: 83.76.137.170 X-Original-NNTP-Posting-Host: 83.76.137.170 Message-ID: <480823e4_3@news.bluewin.ch> X-Trace: news.bluewin.ch 1208493028 83.76.137.170 (18 Apr 2008 06:30:28 +0200) Organization: Bluewin AG Complaints-To: abuse@bluewin.ch X-Original-NNTP-Posting-Host: 127.0.0.1 Path: g2news1.google.com!news3.google.com!feeder3.cambrium.nl!feeder1.cambrium.nl!feed.tweaknews.nl!newsfeed-0.progon.net!progon.net!news-zh.switch.ch!switch.ch!news.ip-plus.net!newsfeed.ip-plus.net!news.bluewin.ch!not-for-mail Xref: g2news1.google.com comp.lang.ada:20984 Date: 2008-04-18T06:30:34+02:00 List-Id: amado.alves@gmail.com: > The eigenvector solvers in Ada.Numerics.Generic_Real_Arrays require > *symmetric* matrices! This is extremely silly. The world is full of > nonsymmetric matrices. I've got a bunch of them to solve. Some very > large, e.g. 1000x1000. Suggestions welcome. Thanks a lot. As other people answered, solving a symmetric matrix is another science than a asymmetric one. But also when the matrices get big, other storages (than array (Integer range <>, Integer range <>) of...) can be a better solution, like band or sparse matrices. In some areas a 10_000 x 10_000 matrix is a toy one, for testing small examples (e.g. solving a physics equation on a 100x100 grid)... ______________________________________________________________ Gautier -- http://www.mysunrise.ch/users/gdm/index.htm Ada programming -- http://www.mysunrise.ch/users/gdm/gsoft.htm NB: For a direct answer, e-mail address on the Web site!