int main(void) {
double array[SIZE] = {20.0, 17.66, 8.2, 15.3, 22.22};
printf("The original array:\n");
show_array(array, SIZE);
mult_array(array, SIZE, 2.5);
printf("The array after calling mult_array():\n");
show_array(array, SIZE);
return EXIT_SUCCESS;
}
int main (void)
{
double dip[SIZE] = {20.0, 17.66, 8.2, 15.3, 22.22};
printf("The original dip array:\n");
show_array (dip, SIZE);
mult_array (dip, SIZE, 2.5);
printf("The dip array after calling mult_array():\n");
show_array(dip, SIZE);
return 0;
}
int main(int argc,char **argv)
{
#ifndef SINGLE_PREC
double *A,*B,*p,*C;
#else
float *A,*B,*p,*C;
#endif
int i,j,k,x,y,z,nx,ny,nz,proc_id,nproc,dims[2],ndim,nu;
int istart[3],isize[3],iend[3];
int fstart[3],fsize[3],fend[3];
int iproc,jproc,ng[3],kmax,iex,conf,m,n;
long int Nglob,Ntot;
double pi,twopi,sinyz;
double *sinx,*siny,*sinz,factor;
double rtime1,rtime2,gt[12],gt1[12],gt2[12],timers[12];
double tcomm,gtcomm[3];
double cdiff,ccdiff,ans,prec;
FILE *fp;
unsigned char op_f[]="fft", op_b[]="tff";
int memsize[3];
#ifndef SINGLE_PREC
void print_all(double *,long int,int,long int),mult_array(double *,long int,double);
#else
void print_all(float *,long int,int,long int),mult_array(float *,long int,double);
#endif
MPI_Init(&argc,&argv);
MPI_Comm_size(MPI_COMM_WORLD,&nproc);
MPI_Comm_rank(MPI_COMM_WORLD,&proc_id);
pi = atan(1.0)*4.0;
twopi = 2.0*pi;
for(i=0; i< 12; i++) {
gt[i] = 0.0;
gt1[i] = 0.0;
gt2[i] = 1E10;
}
Cset_timers();
if(proc_id == 0) {
if((fp=fopen("stdin", "r"))==NULL){
printf("Cannot open file. Setting to default nx=ny=nz=128, ndim=2, n=1.\n");
nx=ny=nz=128; n=1;
} else {
fscanf(fp,"%d %d %d %d %d\n",&nx,&ny,&nz,&ndim,&n);
fclose(fp);
}
#ifndef SINGLE_PREC
printf("Double precision\n (%d %d %d) grid\n %d proc. dimensions\n%d repetitions\n",nx,ny,nz,ndim,n);
#else
printf("Single precision\n (%d %d %d) grid\n %d proc. dimensions\n%d repetitions\n",nx,ny,nz,ndim,n);
#endif
}
MPI_Bcast(&nx,1,MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&ny,1,MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&nz,1,MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&n,1,MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&ndim,1,MPI_INT,0,MPI_COMM_WORLD);
if(ndim == 1) {
dims[0] = 1; dims[1] = nproc;
}
else if(ndim == 2) {
fp = fopen("dims","r");
if(fp != NULL) {
if(proc_id == 0)
printf("Reading proc. grid from file dims\n");
fscanf(fp,"%d %d\n",dims,dims+1);
fclose(fp);
if(dims[0]*dims[1] != nproc)
dims[1] = nproc / dims[0];
}
else {
if(proc_id == 0)
printf("Creating proc. grid with mpi_dims_create\n");
dims[0]=dims[1]=0;
MPI_Dims_create(nproc,2,dims);
if(dims[0] > dims[1]) {
dims[0] = dims[1];
dims[1] = nproc/dims[0];
}
}
}
if(proc_id == 0)
printf("Using processor grid %d x %d\n",dims[0],dims[1]);
/* Initialize P3DFFT */
Cp3dfft_setup(dims,nx,ny,nz,MPI_Comm_c2f(MPI_COMM_WORLD),nx,ny,nz,1,memsize);
/* Get dimensions for input array - real numbers, X-pencil shape.
Note that we are following the Fortran ordering, i.e.
the dimension with stride-1 is X. */
/* printf("Calling get_dims 1\n"); */
conf = 1;
Cp3dfft_get_dims(istart,iend,isize,conf);
/* Get dimensions for output array - complex numbers, Z-pencil shape.
Stride-1 dimension could be X or Z, depending on how the library
was compiled (stride1 option) */
/* printf("Calling get_dims 2\n"); */
conf = 2;
Cp3dfft_get_dims(fstart,fend,fsize,conf);
/* printf("Allocating\n"); */
/* Allocate and Initialize */
#ifndef SINGLE_PREC
A = (double *) malloc(sizeof(double) * isize[0]*isize[1]*isize[2]);
B = (double *) malloc(sizeof(double) * fsize[0]*fsize[1]*fsize[2]*2);
C = (double *) malloc(sizeof(double) * isize[0]*isize[1]*isize[2]);
#else
A = (float *) malloc(sizeof(float) * isize[0]*isize[1]*isize[2]);
B = (float *) malloc(sizeof(float) * fsize[0]*fsize[1]*fsize[2]*2);
C = (float *) malloc(sizeof(float) * isize[0]*isize[1]*isize[2]);
#endif
if(A == NULL)
printf("%d: Error allocating array A (%d)\n",proc_id,isize[0]*isize[1]*isize[2]);
if(B == NULL)
printf("%d: Error allocating array B (%d)\n",proc_id,fsize[0]*fsize[1]*fsize[2]*2);
if(C == NULL)
printf("%d: Error allocating array C (%d)\n",proc_id,isize[0]*isize[1]*isize[2]);
/* printf("Initializing\n"); */
sinx = malloc(sizeof(double)*nx);
siny = malloc(sizeof(double)*ny);
sinz = malloc(sizeof(double)*nz);
for(z=0;z < isize[2];z++)
sinz[z] = sin((z+istart[2]-1)*twopi/nz);
for(y=0;y < isize[1];y++)
siny[y] = sin((y+istart[1]-1)*twopi/ny);
for(x=0;x < isize[0];x++)
sinx[x] = sin((x+istart[0]-1)*twopi/nx);
p = A;
for(z=0;z < isize[2];z++)
for(y=0;y < isize[1];y++) {
sinyz = siny[y]*sinz[z];
for(x=0;x < isize[0];x++)
*p++ = sinx[x]*sinyz;
}
Ntot = fsize[0]*fsize[1];
Ntot *= fsize[2]*2;
Nglob = nx * ny;
Nglob *= nz;
factor = 1.0/Nglob;
rtime1 = 0.0;
for(m=0;m < n;m++) {
if(proc_id == 0)
printf("Iteration %d\n",m);
MPI_Barrier(MPI_COMM_WORLD);
rtime1 = rtime1 - MPI_Wtime();
/* compute forward Fourier transform on A, store results in B */
Cp3dfft_ftran_r2c(A,B,op_f);
rtime1 = rtime1 + MPI_Wtime();
if(proc_id == 0)
printf("Result of forward transform\n");
print_all(B,Ntot,proc_id,Nglob);
/* normalize */
mult_array(B,Ntot,factor);
/* Compute backward transform on B, store results in C */
MPI_Barrier(MPI_COMM_WORLD);
rtime1 = rtime1 - MPI_Wtime();
Cp3dfft_btran_c2r(B,C,op_b);
rtime1 = rtime1 + MPI_Wtime();
}
/* free work space */
Cp3dfft_clean();
/* Check results */
cdiff = 0.0; p = C;
for(z=0;z < isize[2];z++)
for(y=0;y < isize[1];y++) {
sinyz =siny[y]*sinz[z];
for(x=0;x < isize[0];x++) {
ans = sinx[x]*sinyz;
if(cdiff < fabs(*p - ans))
cdiff = fabs(*p - ans);
p++;
}
}
Cget_timers(timers);
#ifndef SINGLE_PREC
MPI_Reduce(&cdiff,&ccdiff,1,MPI_DOUBLE,MPI_MAX,0,MPI_COMM_WORLD);
#else
MPI_Reduce(&cdiff,&ccdiff,1,MPI_REAL,MPI_MAX,0,MPI_COMM_WORLD);
#endif
if(proc_id == 0) {
#ifndef SINGLE_PREC
prec = 1.0e-14;
#else
prec = 1.0e-5;
#endif
if(ccdiff > prec * Nglob*0.25)
printf("Results are incorrect\n");
else
printf("Results are correct\n");
printf("max diff =%g\n",ccdiff);
}
/* Gather timing statistics */
MPI_Reduce(&rtime1,&rtime2,1,MPI_DOUBLE,MPI_MAX,0,MPI_COMM_WORLD);
for (i=0;i < 12;i++) {
timers[i] = timers[i] / ((double) n);
}
MPI_Reduce(&timers,>,12,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
MPI_Reduce(&timers,>1,12,MPI_DOUBLE,MPI_MAX,0,MPI_COMM_WORLD);
MPI_Reduce(&timers,>2,12,MPI_DOUBLE,MPI_MIN,0,MPI_COMM_WORLD);
tcomm = (timers[1]+timers[2]+timers[3]+timers[4]);
MPI_Reduce(&timers,>,12,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
for (i=0;i < 12;i++) {
gt[i] = gt[i]/ ((double) nproc);
}
if(proc_id == 0) {
printf("Time per loop=%lg\n",rtime2/((double) n));
for(i=0;i < 12;i++) {
printf("timer[%d] (avg/max/min): %lE %lE %lE\n",i+1,gt[i],gt1[i],gt2[i]);
}
}
MPI_Finalize();
}