Serial source code

Serial source code

C source 

/*
 *    It evolves the equation:
 *                            u,t + u,x + u,y = 0
 *    Using a Lax scheme.
 *    The initial data is a cruddy gaussian.
 *    Boundaries are flat: copying the value of the neighbour
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define NX 100
#define NY 100
#define LX 2.0
#define LY 2.0

#define sigma 0.1
#define tmax 100


/* 
 * conversions from discrete to real coordinates
 */
float ix2x(int ix){
    return ((ix-1) - (NX-1) / 2.0)*LX/(NX-1);
}

float iy2y(int iy){ 
    return ((iy-1) - (NY-1) / 2.0)*LY/(NY-1);
}


/* Function for evaluating the results that calculates the sum of the array values */
float summa(int nx, int ny, float* val){
float summma=0.0;
int ix,iy;
    for(iy=1;iy<=ny;++iy)
	for(ix=1;ix<=nx;++ix){
          summma+=val[((nx+2)*iy)+ix];
 } 
  return(summma);
}


/* 
 * initialize the system with a gaussian temperature distribution 
 */
int init_transport(float *temp){ 
    int ix,iy;
    float x,y;

    for(iy=1;iy<=NY;++iy)
	for(ix=1;ix<=NX;++ix){
	    x=ix2x(ix);
	    y=iy2y(iy);
	    temp[((NX+2)*iy)+ix] = tmax*exp((-((x*x)+(y*y)))/(2.0*(sigma*sigma)));
	}
    return 0;
}

/*
 * save the temperature distribution
 * the ascii format is suitable for splot gnuplot function
 */
int save_gnuplot(char *filename, float *temp) {
    int ix,iy;
    FILE *fp;

    fp = fopen(filename, "w");   
    for(iy=1;iy<=NY;++iy){		
	for(ix=1;ix<=NX;++ix)
	    fprintf(fp, "\t%f\t%f\t%g\n", ix2x(ix), iy2y(iy), temp[((NX+2)*iy)+ix]);
	fprintf(fp, "\n");
    }
    fclose(fp);

    return 0;
}

int update_boundaries_FLAT(float *temp){
    int ix=0, iy=0;

    for(iy=0;iy<=NY+1;++iy){
	temp[(NX+2)*iy] = temp[((NX+2)*iy)+1];
	temp[((NX+2)*iy)+(NX+1)] = temp[((NX+2)*iy)+NX];
    }
    
    for(ix=0;ix<=NX+1;++ix){
	temp[ix] = temp[(NX+2)+ix];
	temp[((NX+2)*(NY+1))+ix] = temp[((NX+2)*NY)+ix];
    }
    return 0;
}


int evolve(float dtfact, float *temp, float *temp_new){
    float dx, dt;
    int ix, iy;
    float temp0;

    dx = 2*LX/NX;
    dt = dtfact*dx/sqrt(3.0);
    for(iy=1;iy<=NY;++iy)
	for(ix=1;ix<=NX;++ix){
	    temp0 = temp[((NX+2)*iy)+ix];
	    temp_new[((NX+2)*iy)+ix] = temp0-0.5*dt*(temp[((NX+2)*(iy+1))+ix]
            -temp[((NX+2)*(iy-1))+ix]+temp[((NX+2)*iy)+(ix+1)]-temp[((NX+2)*iy)+(ix-1)])/dx;
	}

    for(iy=0;iy<=NY+1;++iy)
	for(ix=0;ix<=NX+1;++ix)
	    temp[((NX+2)*iy)+ix] = temp_new[((NX+2)*iy)+ix];
    

    return 0;
}

int main(int argc, char* argv[]){
    int i=0, nRow=NX+2, nCol=NY+2;
    float *temp, *temp_new;


    temp = (float *) malloc (nRow*nCol*sizeof(float));
    temp_new = (float *) malloc (nRow*nCol*sizeof(float));

    init_transport(temp);
    update_boundaries_FLAT(temp);

    float before=summa(NX, NY, temp);
    printf(" sum temp before: %f\n",before);

    save_gnuplot("transport.dat", temp);

    for(i=1;i<=500;++i) {
        evolve(0.1, temp, temp_new);
        update_boundaries_FLAT(temp);
    }

    float after=summa(NX, NY, temp);
    printf(" sum temp after: %f\n",after);
    save_gnuplot("transport_end.dat", temp);
 
  
    free(temp);
    free(temp_new);    
    return 0;
}

Fortran source 

!
!     It evolves the equation:
!                             u,t + u,x + u,y = 0
!     Using a Lax scheme.
!     The initial data is a cruddy gaussian.
!     Boundaries are flat: copying the value of the neighbour
!

module transport
  implicit none
  save

  integer, parameter :: NX=100
  integer, parameter :: NY=100
  real, parameter    :: LX=2.0
  real, parameter    :: LY=2.0

  real temp(0:NX+1 , 0:NY+1)
  real temp_new(0:NX+1 , 0:NY+1)


CONTAINS
  !conversions from discrete to real coordinates

  real function ix2x(ix)
    integer ix
    ix2x = ((ix-1)-(NX-1)/ 2.0)*LX/(NX-1)
  end function ix2x

  real function iy2y(iy)
    integer iy
    iy2y = ((iy-1)-(NY-1)/ 2.0)*LY/(NY-1)
  end function iy2y


 ! initialize the system with a gaussian temperature distribution

  subroutine init_transport
    integer ix,iy
    real x,y
    real,parameter :: sigma = 0.1
    real,parameter :: tmax = 100

    do iy=1,NY
       do ix=1,NX
          x=ix2x(ix)
          y=iy2y(iy)
          temp(ix,iy) = tmax*exp(-(x**2+y**2)/(2.0*sigma**2))
       enddo
    enddo

  end subroutine init_transport

  ! save the temperature distribution
  ! the ascii format is suitable for splot gnuplot function
  subroutine save_gnuplot(filename)

    character(len=*) filename
    integer ix,iy

    open(unit=20,file=filename,form='formatted')
    do iy=1,NY
       do ix=1,NX
          write(20,*) ix2x(ix),iy2y(iy),temp(ix,iy)
       enddo
       write(20,*)
    enddo

    close(20)
  end subroutine save_gnuplot

  subroutine update_boundaries_FLAT
    temp(0   , 1:NY) = temp(1  , 1:NY)
    temp(NX+1, 1:NY) = temp(NX   , 1:NY)

    temp(1:NX , 0)    = temp(1:NX , 1)
    temp(1:NX , NY+1) = temp(1:NX , NY)
  end subroutine update_boundaries_FLAT

  subroutine evolve(dtfact)
    real :: dtfact
    real :: dx,dt
    integer :: ix,iy
    real :: temp0


    dx = 2*LX/NX
    dt = dtfact*dx/sqrt(3.0)
    do iy=1,NY
       do ix=1,NX
          temp0 = temp(ix,iy)
          temp_new(ix,iy) = temp0 - 0.5 * dt * (temp(ix+1,iy)-temp(ix-1,iy)+temp(ix,iy+1)-temp(ix,iy-1)) / dx
       enddo
    enddo

    temp = temp_new

  end subroutine evolve
end module transport

program prova
  use transport
  implicit none

  integer i

  call init_transport
  call update_boundaries_FLAT
  write(*,*) 'sum temp before',sum(temp(1:NX,1:NY))
  call save_gnuplot('transport.dat')

  do i=1,500
     call evolve(0.1)
     call update_boundaries_FLAT
  enddo

  call save_gnuplot('transport_end.dat')
  write(*,*) 'sum temp after',sum(temp(1:NX,1:NY))

end program prova

Jobscript template (FERMI)

#!/bin/bash
# @ job_type=bluegene
# @ bg_size=64
# @ wall_clock_limit = 00:10:00
# @ account_no =
# @ queue
module load bgq-gnu zlib
runjob --np 1 --env-all : ./transport-serial.x

Jobscript template (PLX)

#!/bin/bash
#PBS -N transser
#PBS -l select=1:ncpus=1:mpiprocs=1
#PBS -l walltime=0:10:00
#PBS -A 
#PBS -q debug

cd $PBS_O_WORKDIR

./transport-serial.x