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,FREEMAIL_FROM
	autolearn=ham autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,13ab88b30e0f779d
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-12-27 04:25:39 PST
Path: archiver1.google.com!postnews1.google.com!not-for-mail
From: gautier_niouzes@hotmail.com (Gautier)
Newsgroups: comp.lang.ada
Subject: Re: Efficient Matrix?
Date: 27 Dec 2002 04:25:39 -0800
Organization: http://groups.google.com/
Message-ID: <17cd177c.0212270425.43d8ee1@posting.google.com>
References: <3e0b2a66_4@news.bluewin.ch>
NNTP-Posting-Host: 213.173.163.2
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: posting.google.com 1040991939 26080 127.0.0.1 (27 Dec 2002 12:25:39
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: 27 Dec 2002 12:25:39 GMT
Xref: archiver1.google.com comp.lang.ada:32330
Date: 2002-12-27T12:25:39+00:00
List-Id: <comp.lang.ada>

Jonas Gasser:

> A : POINTER_MATRIX := new MATRIX(1..10000,1..5000);
> 
> I initialize a variable A from the type POINTER_MATRIX.
> Now I 'm interested to know if this is a common way of creating matrixes and
> if there is a faster and efficient way to handle this or if you have some
> ideas to optimize this.

Briefly, there is not _one_ answer to this (read also the other replies...),
but depending on your data density, computer RAM and CPU cache, the "best"
can be
- your MATRIX
- your MATRIX with pragma pack (smaller but machine code access to data
  possibly more complicated)
- a band matrix
- a sparse matrix
- ... ?

Code for both are in mathpaqs.zip below - just change
the Digits <> into Boolean.
________________________________________________________
Gautier  --  http://www.mysunrise.ch/users/gdm/gsoft.htm

NB: For a direct answer, e-mail address on the Web site!