Re: Mathpaqs release 13-Mar-2018

[gautier_niouzes@hotmail.com]

Hi Vincent,

> Just a few questions :
> - why not use the standard Generic Real Arrays ?
Good point! I'll update the web site with a remark from g_matrices.ads: "NB: For Ada 2005+ and real numbers implemented as floating-point numbers, it is better to use Ada.Numerics.Generic_Real_Arrays instead.". An usage of G_Matrices can be for complex, rational, "bignum"-rationals, etc. ...

> - Are the G_Matrices stored in Fortran convention, i.e. Column Major Order ?
By default not, but you can add a pragma Convention.

> - Are they compatible with Blas & Lapack ?
Some stuff in the lin_alg area is, but frankly it is a bit rusty (in my head)...

> - Are the SparseB matrices compatible with Matlab matrices (i.e. CSC matrices)
SparseB is just a helper for Sparse package (I did it in Ada 83 around end 1990's, it would be a private child package now (tbd)...).
There are two bodies for sparseb: one standalone, one using Blas (sparseb.blas.adb)

> - Are both format interoperable ?
> - Are they interchangeable, i.e is there a common class type to manipulate them?

I've used for research purposes, interchangeably:
- plain matrices,
- band matrices (a matrix with zeroes outside diagonals and the cells just above and below) and
- sparse matrices.
I did it through generics.