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 05:57:06 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.airnews.net!cabal12.airnews.net!usenet From: "John R. Strohm" Newsgroups: comp.lang.ada Subject: Re: Is ther any sense in *= and matrices? Date: Thu, 5 Jun 2003 07:33:39 -0500 Organization: Airnews.net! at Internet America Message-ID: References: Abuse-Reports-To: abuse at airmail.net to report improper postings NNTP-Proxy-Relay: library2.airnews.net NNTP-Posting-Time: Thu, 05 Jun 2003 07:55:32 -0500 (CDT) NNTP-Posting-Host: ![7:`1k-WpiJK!( (Encoded at Airnews!) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Xref: archiver1.google.com comp.lang.ada:38676 Date: 2003-06-05T07:33:39-05:00 List-Id: "Preben Randhol" wrote in message news:slrnbduaav.6dd.randhol+abuse@kiuk0152.chembio.ntnu.no... > Vinzent Hoefler wrote: > > Preben Randhol wrote: > > > >>I mean even if one define "*" for Matrix_Type one cannot do: > >> > >> A := A * B > > > > You can, iff A and B are square matrices. > > Yes, but that is a special case. Not quite. A[m x n] = B[m x p] * C[p x n] You would want *= to work for a general result, which is A[m x n] = A[m x n] * B[n x n] If the matrices are not compatible for multiplication, then their product is not mathematically defined, at all. Usually, of course, you are only interested in square matrices.