PRACE NPT

#include "mpiargs.h"

void sizoff( int n1, int n2 )

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

// --- Routine 'sizoff' determines the sizes and offsets of a 2-D

//     array with dimensions 'n1' and 'n2' with respect to a

//     distribution that is as even as possible on 'nodes' processors

//     Then the offsets for each local array with respect to the global

//     array are determined.

//     Entry 'sizes[i][0]' giving the size for the i-th slice and 1-st

//     dimension, etc.

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

{

   int i, k, non, nrest, rest;

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

   non   = n1/nodes;

   rest  = n1%nodes;

   nrest = nodes - rest - 1;

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

      sizes[i][0] = non;

      if ( i > nrest ) sizes[i][0] = non + 1;

   }

   non   = n2/nodes;

   rest  = n2%nodes;

   nrest = nodes - rest - 1;

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

      sizes[i][1] = non;

      if ( i > nrest ) sizes[i][1] = non + 1;

   }

   for( k = 0; k < 2; k++ ) {

      offset[0][k] = 0;

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

         offset[i][k] = offset[i-1][k] + sizes[i-1][k];

      }

   }

}