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Newsgroups: comp.lang.ada
Date: Mon, 22 Jul 2019 10:27:02 -0700 (PDT)
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Subject: Re: The answer to "Can Ada replace FORTRAN for numerical computation?
From: Lucretia <laguest9000@googlemail.com>
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Xref: reader01.eternal-september.org comp.lang.ada:56916
Date: 2019-07-22T10:27:02-07:00
List-Id: <comp.lang.ada>

On Monday, 22 July 2019 14:20:14 UTC+1, Simon Wright  wrote:
> >> I can't believe that the visible complaint (the ordering convention for
> >> matrices, row- vs column-major) would seriously impact the mental
> >> dexterity required to write mathematical code.
> >> 
> >> And now we have Convention (Fortran), which makes it not-too-hard to
> >> interface to existing Fortran code.
> >
> > Wouldn't Ada also require multi-dimensional slices? Something I've
> > been wanting for a while, albeit in limited form, 2D/3D for
> > images/textures.
> 
> I _think_ this is what the Fortran PACK/UNPACK & RESHAPE packages are
> for; for example [1]. Interesting that the representation of the
> matrices looks row-major!
> 
> The pre- and post-conditions might be a challenge.
> 
> [1] https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-unpack

Something like:

M2 := M4 (1, 1 .. 2, 2); -- Makes a copy into the Matrix 2x2 type from a 4x4.