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-Thread: 103376,4246083efae0e43b X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!postnews1.google.com!not-for-mail From: jpwoodruff@irisinternet.net (John Woodruff) Newsgroups: comp.lang.ada Subject: Re: Singular Value Decomposition (SVD) Ada Algorithm Date: 31 Oct 2004 10:01:30 -0800 Organization: http://groups.google.com Message-ID: <34defe4d.0410311001.36e3680@posting.google.com> References: <35f054ea.0410290918.5f7f7d0@posting.google.com> <34defe4d.0410300854.5c038648@posting.google.com> <35f054ea.0410302259.7510a56e@posting.google.com> NNTP-Posting-Host: 216.126.128.53 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1099245691 11933 127.0.0.1 (31 Oct 2004 18:01:31 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 31 Oct 2004 18:01:31 +0000 (UTC) Xref: g2news1.google.com comp.lang.ada:5937 Date: 2004-10-31T10:01:30-08:00 List-Id: aschwarz@acm.org (skidmarks) wrote in message news:<35f054ea.0410302259.7510a56e@posting.google.com>... > > > > You can acquire the Drexel U Matrix Math items from > > http://dflwww.ece.drexel.edu/research/ada/ > > They are marked: > > -- Copyright (c) Drexel University, 1996 > > Their package Generic_Real_Arrays.Operations defines a subprogram > > "Singular_Value_Decomposition". > > > > This might be what you want! > > Thank you. I haven't looked closely but have looked enough (to say) it > seems to be what I need. > > By-the-by, any reason that you made it a generic package? Well, it wasn't I who did the making. But I'll offer the "conventional" explanation: application writers are wise to select specific types to represent the numeric quantities, and the generic formal in such packages as "generic_real_arrays" is instantiated to reflect those application-specific types. <...> I developed a > doubly-linked list. List management is a normal package body. The > generic package provides space, in the generic body, and interfaces to > the non-generic list manager. The effect is to have a no-cost generic > package interfacing with a shared non-generic package. I'm not sure I followed that claim; you might consider posting an example (folks here are pretty constructive, so you won't get pilloried :) However when I read "generic package provides space", I interpret that to mean maybe you're coercing lots of different "components" of some list, using 'address' to manage memory (?). If that's your suggestion, I don't think I'll agree. In any event, I don't think there is a "cost" argument in favor of avoiding generics -- but I'm interested in the discussion. John