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 X-Google-Thread: 103376,8c8550b9f2cf7d40 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-06-05 13:17:32 PST Path: archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-06!sn-post-01!supernews.com!corp.supernews.com!not-for-mail From: "David C. Hoos" Newsgroups: comp.lang.ada Subject: Re: Is ther any sense in *= and matrices? Date: Thu, 5 Jun 2003 15:17:27 -0500 Organization: Posted via Supernews, http://www.supernews.com Message-ID: References: X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Complaints-To: abuse@supernews.com Xref: archiver1.google.com comp.lang.ada:38734 Date: 2003-06-05T15:17:27-05:00 List-Id: "Wesley Groleau" wrote in message news:qgqdnUqY3I2EBEKjXTWcpg@gbronline.com... > > >>I mean even if one define "*" for Matrix_Type one cannot do: > >> > >> A := A * B > > > > You can, iff A and B are square matrices. > > But you cannot do it efficiently "in-place" > because each element in the result is the sum > of multiply operators on several pairs of > elements in the two addends. So if I compute The operands of * are called "factors", not "addends." > > A(1,1) before A (1,2) then the latter has already > had one of its inputs changed. To overcome this > without introducing a temporary "A" one would > require a rather complicated set of temporary > _parts_ of A. > > _______________________________________________ > comp.lang.ada mailing list > comp.lang.ada@ada.eu.org > http://ada.eu.org/mailman/listinfo/comp.lang.ada >