PRACE NPT

#include <stdlib.h>

#include <stdio.h>

double rand64( void );

void getmatvec( int ncols, int nrows, int nelmts, int indx[], int rowp[],

                double matvals[], double invec[] )

{

   int    felprow, i, nvarelts;

// -----------------------------------------------------------------------

   felprow  = (int)(0.80*nelmts/nrows) + 1;

   nvarelts = felprow/2 + 1;

   setrand( 2003 );

// --- Generate the rowpointers subject to a variability of 20% in the

//     number of elements per row.    

   rowp[0] = 1;

   for( i = 1; i < nrows; i++ ) {

      rowp[i] = rowp[i-1] + felprow +

                            (int)( nvarelts*( rand64() - 0.5 ));

   }

// --- Be sure that the last rowpointer is <= nelmts.

   rowp[nrows-1] = ( rowp[nrows-1] <= nelmts ) ? rowp[nrows-1] : nelmts;

// --- Generate index array 'indx' and array with matrix entries 'matvals'.

   for( i = 0; i < nelmts; i++ ) {

      indx[i]    = (int)( ncols*rand64() );

      matvals[i] = 1.0;

   }

// --- Generate input vector 'invec'.

   for( i = 0; i < ncols; i++ ) {

      invec[i] = 1.0;

   }

}