void calculate_fermion_force()
{
int i;
double fft[GRIDPOINTS];
double ffx[GRIDPOINTS];
double ffy[GRIDPOINTS];
for(i=0; i<GRIDPOINTS; i++)
{
g_R[i] = (gauss() + I*gauss())/sqrt(2); //Pseudofermion fields times M^{-1}
};
fermion(g_fermion, g_R); //g_fermion the pseudofermion field, i.e. phi = M R
//g_cgiterations1 += cg(g_eta, g_fermion, ITER_MAX, DELTACG, &fermion_sqr);
for(i = 0; i < GRIDPOINTS; i++) {
//printf("%d \n", i);
//printf("Brute-force %f\n", stupid_fermion_force_x(i));
//printf("Smart %f\n", fermion_forcex(i));
ffx[i] = stupid_fermion_force_x(i);
printf("Brute-force %d, %f\n", i, ffx[i]);
//fft[i] = fermion_forcet(i);
//ffy[i] = fermion_forcey(i);
}
print_vector_r(ffx);
//print_vector_r(fft);
printf("Max x fermion force: %f\n", max_r(ffx));
//printf("Max t fermion force: %f\n", max_r(fft));
return;
}
Real GreensFunction3DSym::drawR(Real rnd, Real t) const
{
// input parameter range checks.
if ( !(rnd <= 1.0 && rnd >= 0.0 ) )
{
throw std::invalid_argument( ( boost::format( "GreensFunction3DSym: rnd <= 1.0 && rnd >= 0.0 : rnd=%.16g" ) % rnd ).str() );
}
if ( !(t >= 0.0 ) )
{
throw std::invalid_argument( ( boost::format( "GreensFunction3DSym: t >= 0.0 : t=%.16g" ) % t ).str() );
}
// t == 0 or D == 0 means no move.
if( t == 0.0 || getD() == 0.0 )
{
return 0.0;
}
ip_r_params params = { this, t, rnd };
gsl_function F =
{
reinterpret_cast<double (*)(double, void*)>( &ip_r_F ),
¶ms
};
Real max_r( 4.0 * sqrt( 6.0 * getD() * t ) );
while( GSL_FN_EVAL( &F, max_r ) < 0.0 )
{
max_r *= 10;
}
const gsl_root_fsolver_type* solverType( gsl_root_fsolver_brent );
gsl_root_fsolver* solver( gsl_root_fsolver_alloc( solverType ) );
gsl_root_fsolver_set( solver, &F, 0.0, max_r );
const unsigned int maxIter( 100 );
unsigned int i( 0 );
while( true )
{
gsl_root_fsolver_iterate( solver );
const Real low( gsl_root_fsolver_x_lower( solver ) );
const Real high( gsl_root_fsolver_x_upper( solver ) );
const int status( gsl_root_test_interval( low, high, 1e-15,
this->TOLERANCE ) );
if( status == GSL_CONTINUE )
{
if( i >= maxIter )
{
gsl_root_fsolver_free( solver );
throw std::runtime_error("GreensFunction3DSym: drawR: failed to converge");
}
}
else
{
break;
}
++i;
}
//printf("%d\n", i );
const Real r( gsl_root_fsolver_root( solver ) );
gsl_root_fsolver_free( solver );
return r;
}
