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From: Hyman Rosen <hymie@prolifics.com>
Subject: Re: Ada->C++ conversion stats?
Date: 2000/03/21
Message-ID: <t7d7oofl8v.fsf@calumny.jyacc.com>#1/1
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Date: 2000-03-21T14:30:53+00:00
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"Robert L. Klungle" <bklungle@gte.net> writes:
> The C++ version execution time is 3 times slower than the original Ada.
> Primarily due to the implementation of an Array (Matrix) class as a
> Class of Vectors-of-Vectors.
> This was done to keep the matrix type of referencing ([][]). There is no
> C++ operator to overload of this kind.

You should certainly not implement (non-sparse) matrices as vectors
of vectors! I would advise you to get a copy of Barton & Nackman's
"Scientific and Engineering C++". There are all sorts of efficient
algorithms in there for implementing matrices while preserving the
[][] C++ array referencing syntax.