my cheat sheet note on installation of the Ada binding to Blas and Lapack

my cheat sheet note on installation of the Ada binding to Blas and Lapack

[Nasser M. Abbasi]

fyi;

I wrote a small note on the installation of the Ada binding
to Blas and Lapack, in case they might be useful for someone.

Added the note to my Ada web page below

http://12000.org/my_notes/ada/index.htm

The note shows the steps to just install and build the bindings,
and run the tests that came with them. This was using
GNAT 2012 on Linux.

Thanks to Duncan Sands and Wasu Chaopanon for writing the Blas
and Lapack Ada bindings.

--Nasser

Re: my cheat sheet note on installation of the Ada binding to Blas and Lapack

[shai.lesh]

On Friday, July 6, 2012 10:26:58 AM UTC+1, Nasser M. Abbasi wrote:
> fyi;
> 
> I wrote a small note on the installation of the Ada binding
> to Blas and Lapack, in case they might be useful for someone.
> 

Thanks for your efforts. I need to find a way to get LAPACK/BLAS on Windows.

YC

Re: my cheat sheet note on installation of the Ada binding to Blas and Lapack

[Simon Wright]

shai.lesh@gmx.com writes:

> On Friday, July 6, 2012 10:26:58 AM UTC+1, Nasser M. Abbasi wrote:
>> fyi;
>> 
>> I wrote a small note on the installation of the Ada binding
>> to Blas and Lapack, in case they might be useful for someone.
>> 
>
> Thanks for your efforts. I need to find a way to get LAPACK/BLAS on Windows.

I went to [1]; down a page or so to the line "Ref BLAS LAPACK LAPACKE"
and downloaded the BLAS and LAPACK 'win32.dll' links. These worked fine
with the under-work version of gnat-math-extn\test\demo_extensions (you
can check it out using Mercurial from SF at [2]).

This was on an XP Pro SP3 VM under VMware and GNAT GPL 2011. It has
Cygwin installed but the build was OK in a Windows shell.

[1] http://icl.cs.utk.edu/lapack-for-windows/lapack/#libraries_mingw
[2] http://gnat-math-extn.hg.sourceforge.net:8000/hgroot/gnat-math-extn/gnat-math-extn

Re: my cheat sheet note on installation of the Ada binding to Blas and Lapack

[Nasser M. Abbasi]

On 7/6/2012 4:26 AM, Nasser M. Abbasi wrote:
> fyi;
>
> I wrote a small note on the installation of the Ada binding
> to Blas and Lapack, in case they might be useful for someone.
>
> Added the note to my Ada web page below
>
> http://12000.org/my_notes/ada/index.htm
>

fyi;

This is my first program using the lapack binding!

I tried to make it as simple as I can. It solves
A x = b.   (one can do this also using Ada own solve() function
ofcourse, but with Lapack, one can do much more).

I show the Ada code, and the matlab equivalent to show they
give the same result. I'll update my cheat sheet above with
these examples later on.

----------------------------------
with Ada.Text_IO;  use  Ada.Text_IO;

with Interfaces.Fortran; use Interfaces.Fortran;
with labase; -- from LAPACK binding
with ladrv;  -- from LAPACK binding

procedure mySolve is
	
   A:   labase.Fortran_Real_Matrix ( 1..3, 1..3 );
   b:   labase.Fortran_Real_Matrix ( 1..3, 1..1  );	
   package Real_IO is new Ada.Text_IO.Float_IO( Real );
   INFO : Fortran_Integer;
   IPIV : labase.Fortran_Integer_Vector ( 1..A'Last(2)); 	

   Begin -- solve A x=b
           
	A := ((2.0,  3.0,  1.0),
               (2.0,  1.0,  1.0),
               (4.0, -1.0,  6.0));

	b := ((9.0,others=>0.0),
               (2.0,others=>0.0),
               (-2.0,others=>0.0)
               );
     
         ladrv.SGESV ( N   => A'Last(2),
                      NRHS => b'Last(2),
                      A    => A,
                      LDA  => A'Last(1),
                      IPIV => IPIV,
                      B    => b,
                      LDB  => b'Last(1),
                      INFO => INFO);

   	if ( not(INFO = 0) ) then
	   raise PROGRAM_ERROR;
	end if;

         for x of b loop  -- print solution
             real_io.PUT ( x ); new_line;
         end loop;
                     
end mySolve;
--------------------------
output is

>gnatmake -gnat2012 -I../ada  mysolve.adb
gcc -c -gnat2012 -I../ada mysolve.adb
gnatbind -I../ada -x mysolve.ali
gnatlink mysolve.ali

>./mysolve
-1.31250E+00
  3.50000E+00
  1.12500E+00
>


Matlab
--------
EDU>> A=[2 3 1;2 1 1;4 -1 6];
EDU>> b=[9;2;-2];
EDU>> A\b   -- This is Matlab API to SGESV

ans =

   -1.312500000000000
    3.500000000000000
    1.125000000000000

------------

So we see that Matlab is correct, as confirmed by Ada :)

--Nasser

Re: my cheat sheet note on installation of the Ada binding to Blas and Lapack

[Simon Wright]

"Nasser M. Abbasi" <nma@12000.org> writes:

> This is my first program using the lapack binding!

Great!

>           ladrv.SGESV ( N   => A'Last(2),
>                      NRHS => b'Last(2),
>                      A    => A,
>                      LDA  => A'Last(1),
>                      IPIV => IPIV,
>                      B    => b,
>                      LDB  => b'Last(1),
>                      INFO => INFO);

Better to use 'Length rather than 'Last (just in case your matrices'
index range doesn't start at 1). 

>   	if ( not(INFO = 0) ) then
> 	   raise PROGRAM_ERROR;
> 	end if;

As a matter of style, better as

   if INFO /= 0 then

Re: my cheat sheet note on installation of the Ada binding to Blas and Lapack

[Ada novice]

On Sunday, July 8, 2012 1:50:03 AM UTC+1, Nasser M. Abbasi wrote:
> On 7/6/2012 4:26 AM, Nasser M. Abbasi wrote:
> > fyi;
> >
> > I wrote a small note on the installation of the Ada binding
> > to Blas and Lapack, in case they might be useful for someone.

> This is my first program using the lapack binding!
> 

I am still struggling to have Lapack/blas on Windows and perhaps they will never work! I am happy of your motivation and persistence in showing how to interface these libraries and Ada. Here are some examples that you may want to try:

http://www.nag.com/lapack-ex/lapack-ex.html

YC