AMD dependency information

[ivan-pi]

The README doesn't specify in any detail how to obtain a copy of the AMD ordering routine. Adding a link to the SuiteSparse homepage, or the AMD User Guide from the SuiteSparse Github repository would be helpful.

I've noticed that only the C interface (i.e. "amd.h") is actually needed:

psblas3/util/psb_amd_order.c

Line 33 in b05679f

#include "amd.h"

The AMD package provided in SuiteSparse however also includes two F77 routines, and a similar routine MC47 can be found in the Harwell Subroutine Library. I would recommend emphasizing that the C interface is used.

Otherwise one can get easily confused by the early versions of the AMD package which can be found in the linalg/amd/ folder on Netlib, or directly from ACM TOMS Algorithm 837: AMD (Netlib mirror: toms/837).

[sfilippone]

Will have to update the docs before the next release.

[sfilippone]

BTW, the C version does not overwrite the input matrix (the Fortran version does according to the SuiteSparse docs).
In any case, AMD is an optional package

[sfilippone]

I added a small note in branch maint-3.8.0/README. Would you mind checking it is OK?
If it is satisfactory, I'll publish 3.8.0-2

[ivan-pi]

Better than nothing. SuiteSparse and AMD are quite common so it should suffice.