void run_sim( const params_t *par, const double *hz, const double *hhxh, double complex *psi ){
uint64_t i, N;//, dim = 1 << (par->nQ);
double complex cz, cx, im=(-(par->dt)*I), fac=1.0/(par->dim);
double t0, t1;
N = (uint64_t)((par->T) / (par->dt));
cz = ( im/2.0 )*B(0);
expMatTimesVec( par->dim, cz, 1.0, hz, psi ); //apply Z part
for( i = 0; i <= N; ++i ){
t0 = i*(par->dt)/(par->T);
t1 = (i+1)*(par->dt)/(par->T);
//Time-dependent coefficients
cz = ( im/2.0 )*( B(t0) + ((i < N) ? B(t1) : 0) );
cx = im * A(t0);
//Evolve system
FWHT( par->nQ, par->dim, psi );
expMatTimesVec( par->dim, cx, 1.0, hhxh, psi ); //apply X part
FWHT( par->nQ, par->dim, psi );
expMatTimesVec( par->dim, cz, fac, hz, psi ); //apply Z part
}
}
/*------------------------------------------------------------------
- Config file format - simplify, don't need xml, but like the structure
{
"scalars" : {
"nq" : 3,
"lrgs" : 4,
"print" : true
"t" : 10.0,
"dt" : 0.1
},
"coefficients" : {
"alpha" : [0.112, 0.234, 0.253],
"beta" : [0.453, 0.533, -0.732, 0.125, -0.653, 0.752],
"delta" : [1.0, 1.0, 1.0]
}
}
------------------------------------------------------------------*/
int main( int argc, char **argv ){
double *hz, *hhxh; /* hamiltonian components */
double *al, *be, *de;
fftw_complex *psi; /* State vector */
fftw_complex factor;
double T = 10.0, dt = 0.1;
uint64_t i, j, k, bcount;
uint64_t nQ=3, N, L=4, dim;
int *fft_dims, prnt=0;
uint64_t testi, testj;
int dzi, dzj; //TODO: consider using smaller vars for flags and these
fftw_plan plan;
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Parse configuration file
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
//TODO: going to need logic to handle incomplete config files
if( argc < 2 ){
fprintf( stderr, "Need a json configuration file. Terminating...\n" );
return 1;
}
/* Parse file and populate applicable data structures */
{
JSON_Value *root_value = NULL;
JSON_Object *root_object;
JSON_Array *array;
root_value = json_parse_file_with_comments( argv[1] );
root_object = json_value_get_object( root_value );
nQ = (uint64_t) json_object_dotget_number( root_object, "scalars.nq" );
prnt = json_object_dotget_boolean( root_object, "scalars.print" );
L = (uint64_t) json_object_dotget_number( root_object, "scalars.lrgs" );
T = json_object_dotget_number( root_object, "scalars.t" );
dt = json_object_dotget_number( root_object, "scalars.dt" );
al = (double *)malloc( nQ*sizeof(double) );
de = (double *)malloc( nQ*sizeof(double) );
be = (double *)malloc( (nQ*(nQ-1)/2)*sizeof(double) );
array = json_object_dotget_array( root_object, "coefficients.alpha" );
if( array != NULL ){
for( i = 0; i < json_array_get_count(array); i++ ){
al[i] = -json_array_get_number( array, i );
}
}
array = json_object_dotget_array( root_object, "coefficients.beta" );
if( array != NULL ){
for( i = 0; i < json_array_get_count(array); i++ ){
be[i] = -json_array_get_number( array, i );
}
}
array = json_object_dotget_array( root_object, "coefficients.delta" );
if( array != NULL ){
for( i = 0; i < json_array_get_count(array); i++ ){
de[i] = -json_array_get_number( array, i );
}
}
json_value_free( root_value );
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Compute the Hamiltonian and state vector for the simulation
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/*
Create state vector and initialize to 1/sqrt(2^n)*(|00...0> + ... + |11...1>)
TODO: keep track of local size and local base
*/
dim = 1 << nQ;
factor = 1.0/sqrt( dim );
fft_dims = (int *)malloc( nQ*sizeof(int) );
psi = (fftw_complex *)malloc( (dim)*sizeof(fftw_complex) );
hz = (double *)calloc( (dim),sizeof(double) );
hhxh = (double *)calloc( (dim),sizeof(double) );
for( i = 0; i < nQ; i++ ){
fft_dims[i] = 2;
}
plan = fftw_plan_dft( nQ, fft_dims, psi, psi, FFTW_FORWARD, FFTW_MEASURE );
/*
Assemble Hamiltonian and state vector
*/
for( k = 0; k < dim; k++ ){
//TODO: when parallelized, k in dzi test will be ~(k + base)
bcount = 0;
for( i = 0; i < nQ; i++ ){
testi = 1 << (nQ - i - 1);
dzi = ((k/testi) % 2 == 0) ? 1 : -1;
hz[k] += al[i] * dzi;
hhxh[k] += de[i] * dzi;
for( j = i; j < nQ; j++ ){
testj = 1 << (nQ - j - 1);
dzj = ((k/testj) % 2 == 0) ? 1 : -1;
hz[k] += be[bcount] * dzi * dzj;
bcount++;
}
}
psi[k] = factor;
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Run the Simulation
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
fftw_complex cz, cx;
double t;
N = (uint64_t)(T / dt);
for( i = 0; i < N; i++ ){
t = i*dt;
//t0 = (i-1)*dt;
//Time-dependent coefficients
cz = (-dt * I)*t/(2.0*T);
cx = (-dt * I)*(1 - t/T);
//Evolve system
expMatTimesVec( psi, hz, cz, dim ); //apply Z part
fftw_execute( plan );
expMatTimesVec( psi, hhxh, cx, dim ); //apply X part
fftw_execute( plan );
expMatTimesVec( psi, hz, cz, dim ); //apply Z part
/*
TODO: can probably get some minor speedup by incorporating this
into expMatTimesVec if needed
*/
scaleVec( psi, 1.0/dim, dim );
}
fftw_destroy_plan( plan );
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Check solution and clean up
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
//TODO: locally, collect all local largests on one
// node, find k largest from that subset
if( prnt && nQ < 6 ){
for( i = 0; i < dim; i++ ){
printf( "psi[%d] = (%f, %f)\t%f\n",
i,
creal( psi[i] ),
cimag( psi[i] ),
cabs( psi[i]*psi[i] ) );
}
} else {
uint64_t *largest = (uint64_t *)calloc( L, sizeof(uint64_t) );
findLargest( largest, psi, dim, L );
for( i = 0; i < L; ++i ){
printf( "psi[%d] = (%f, %f)\t%f\n",
i,
creal( psi[largest[L-1-i]] ),
cimag( psi[largest[L-1-i]] ),
cabs( psi[largest[L-1-i]]*psi[largest[L-1-i]] ) );
}
free( largest );
}
/*
Free work space.
*/
fftw_free( psi );
free( fft_dims );
free( hz );
free( hhxh );
return 0;
}
