[PPL-devel] Fwd: Re: Linear constraint solving example with floating point co-efficients

[Roberto Bagnara]

-------- Original Message --------
Subject: 	Re: [PPL-devel] Linear constraint solving example with floating point co-efficients
Date: 	Wed, 24 Aug 2011 02:55:32 -0400
From: 	Mahesh Nanjundappa <knmahesh at vt.edu>
To: 	Roberto Bagnara <bagnara at cs.unipr.it>



Hello Dr. Bagnara,

Sorry if I bothered you and thanks for getting back to me despite your busy schedule. I've been going through the documentation and the sample examples from past 2 days. My purpose is more than the solving the linear system. But frankly speaking, I've not been to get any simple example compiled with floating point coefficients. I was looking for a pointer to any example which is solved with floating point coefficients.

Again, thanks for getting back to me.

Regards,
Mahesh

On Wed, Aug 24, 2011 at 2:34 AM, Roberto Bagnara <bagnara at cs.unipr.it <mailto:bagnara at cs.unipr.it>> wrote:

     On 08/23/11 15:31, Mahesh Nanjundappa wrote:

         Hi all,

         Please don't feel annoyed by this request. I did try for looking for examples in the folder I downloaded and in the manual. But couldnt find what I was looking for.

         I'm looking for a simple example where a linear constraint system with floating point coefficients (variables can also take floating point values) is solved and output is printed to either file or stdout. I don't have strict requirement to number of decimal points it has to be accurately computed. I'm fine with just 2 decimal points.

         The system can be as simple as this,

         1.2*x + 2.3y <= 8.2
         2.2*x + 1.4*y <= 7.1

         This one example I tried out but with integer coefficients.
         #include <ppl.hh>
         #include "ppl_c.h"

         using namespace Parma_Polyhedra_Library;

         int main()
         {

         Variable x(0);
         Variable y(1);
         Constraint_System CS;

         Linear_Expression LE1 = 1*x + 2*y;
         Linear_Expression LE2 = 2*x + 1*y;

         CS.insert(LE1 <= 7);
         CS.insert(LE2 <= 5);

         C_Polyhedron P(CS);

         return 0;
         }

         It would be great if someone can help me out with this by providing an example or code for the system I described earlier.

         Thanks in advance,
         Mahesh


     Hi Mahesh.

     There is really no way you can use the PPL without even looking
     at its documentation.
     Good luck,

         Roberto

     --
     Prof. Roberto Bagnara
     Applied Formal Methods Laboratory
     Department of Mathematics, University of Parma, Italy
     http://www.cs.unipr.it/~__bagnara/ <http://www.cs.unipr.it/~bagnara/>
     mailto:bagnara at cs.unipr.it <mailto:bagnara at cs.unipr.it>