Path: utzoo!utgpu!watmath!maytag!watstat!dmurdoch
From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Newsgroups: comp.lang.pascal
Subject: Re: Runtime dimensioning and Pascal
Message-ID: <795@maytag.waterloo.edu>
Date: 9 Nov 89 14:24:40 GMT
References: <6354@merlin.usc.edu>
Sender: daemon@maytag.waterloo.edu
Reply-To: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Organization: U. of Waterloo, Ontario
Lines: 23

In article <6354@merlin.usc.edu> ajayshah@aludra.usc.edu () writes:
>
>Pascal is the prettiest language in the universe, but declaring five
>matrix inversion routines is a little tedious.  Any ideas on how to
>get around this?

I haven't actually done this, but it looks as though it shouldn't be too
onerous to declare all your arrays as big one dimensional ones, and do
the indexing yourself.  For example, to pass an n by m array to a routine,
pass a vector of the data, and pass n and m.  Then when you want to access
element x[i,j], instead access x[e(i,j)], where "e" is defined to be a 
little function to do the indexing.  It'll be a little tedious because
you'll either need a separate "e" function for each value of m, or you'll
have to pass m to the routine, but that's not so bad.  Most linear algebra
routines only need one or two column sizes anyways.

If you're using TP and you take the time to code e as an inline assembler 
routine there won't even be much of a speed penalty.  

You could also do something like x(i,j), but I think that would 
incur more overhead, or at least make for more complicated inlines.

Duncan Murdoch