| |
| c--------------------------------------------------------------------- |
| c--------------------------------------------------------------------- |
| |
| subroutine proc_grid |
| |
| c--------------------------------------------------------------------- |
| c--------------------------------------------------------------------- |
| |
| implicit none |
| |
| include 'mpinpb.h' |
| include 'applu.incl' |
| |
| c--------------------------------------------------------------------- |
| c local variables |
| c--------------------------------------------------------------------- |
| integer xdim0, ydim0, IERROR |
| |
| c--------------------------------------------------------------------- |
| c |
| c set up a two-d grid for processors: column-major ordering of unknowns |
| c |
| c--------------------------------------------------------------------- |
| |
| xdim0 = nnodes_xdim |
| ydim0 = nnodes_compiled/xdim0 |
| |
| ydim = dsqrt(dble(num))+0.001d0 |
| xdim = num/ydim |
| do while (ydim .ge. ydim0 .and. xdim*ydim .ne. num) |
| ydim = ydim - 1 |
| xdim = num/ydim |
| end do |
| |
| if (xdim .lt. xdim0 .or. ydim .lt. ydim0 .or. |
| & xdim*ydim .ne. num) then |
| if (id .eq. 0) write(*,2000) num |
| 2000 format(' Error: couldn''t determine proper proc_grid', |
| & ' for nprocs=', i6) |
| CALL MPI_ABORT( MPI_COMM_WORLD, MPI_ERR_OTHER, IERROR ) |
| endif |
| |
| if (id .eq. 0 .and. num .ne. 2**ndim) |
| & write(*,2100) num, xdim, ydim |
| 2100 format(' Proc_grid for nprocs =',i6,':',i5,' x',i5) |
| |
| row = mod(id,xdim) + 1 |
| col = id/xdim + 1 |
| |
| |
| return |
| end |
| |
| |
