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From: "Jerry" <lanceboyle@qwest.net>
Newsgroups: comp.lang.ada
Subject: Re: Why does this work? (overloads)
Date: 8 Feb 2007 02:40:28 -0800
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Date: 2007-02-08T02:40:28-08:00
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Jeffrey R. Carter wrote:
> Jerry wrote:
>
> > Yes, but  time series are usually indexed from 0. Sometimes, the FFT
> > of a time series is indexed from 0 and sometimes -NN/2 .. NN/2-1. When
> > one uses a time series in a vector or matrix, conundrums obviously
> > arise, not only in computer code but in print. I once figured out how
> > to make Pascal let me have it both ways by declaring both types, one
> > type indexed 0..NN-1 and the other 1..NN, and then I set a pointer of
> > one type to an array originally declared with another type. I'm
> > guessing that Ada doesn't allow this, however.
>
> No pointers needed:
>
> A : Vector (0 .. N - 1);
> B : Vector (1 .. A'Length);
>
> A := B;
> B := A;
>
> This is called sliding.
>
Good point. However, it uses twice the memory, and worse, changes made
in A are not reflected in B without repeating the assignment A := B
(correct?) and vice versa. My Pascal trick had neither of these
problems yet carried boundary checking using either name.

Maybe there's a way to do this using unrestricted_access variables of
GNAT.

Jerry