// Same deal: reverse axis order if we have separable interpolant in X domain
void SBInterpolatedImage::fillXGrid(XTable& xt) const
{
#ifdef DANIELS_TRACING
cout << "SBInterpolatedImage::fillXGrid called" << endl;
#endif
if ( dynamic_cast<const InterpolantXY*> (xInterp)) {
int N = xt.getN();
double dx = xt.getDx();
for (int ix = -N/2; ix < N/2; ix++) {
for (int iy = -N/2; iy < N/2; iy++) {
Position<double> x(ix*dx,iy*dx);
xt.xSet(ix,iy,xValue(x));
}
}
} else {
// Otherwise just use the normal routine to fill the grid:
SBProfile::fillXGrid(xt);
}
}
// Fourier transform from (complex) k to x:
// This version takes XTable reference as argument
void KTable::transform(XTable& xt) const
{
check_array();
// check proper dimensions for xt
assert(_N==xt.getN());
// We'll need a new k array because FFTW kills the k array in this
// operation. Also, to put x=0 in center of array, we need to flop
// every other sign of k array, and need to scale.
dbg<<"Before make t_array"<<std::endl;
FFTW_Array<std::complex<double> > t_array(_N);
dbg<<"After make t_array"<<std::endl;
double fac = _dk * _dk / (4*M_PI*M_PI);
long int ind=0;
dbg<<"t_array.size = "<<t_array.size()<<std::endl;
for (int iy=0; iy<_N; iy++) {
dbg<<"ind = "<<ind<<std::endl;
for (int ix=0; ix<=_N/2; ix++) {
if ( (ix+iy)%2==0) t_array[ind]=fac * _array[ind];
else t_array[ind] = -fac* _array[ind];
ind++;
}
}
dbg<<"After fill t_array"<<std::endl;
fftw_plan plan = fftw_plan_dft_c2r_2d(
_N, _N, t_array.get_fftw(), xt._array.get_fftw(), FFTW_ESTIMATE);
dbg<<"After make plan"<<std::endl;
#ifdef FFT_DEBUG
if (plan==NULL) throw FFTInvalid();
#endif
// Run the transform:
fftw_execute(plan);
dbg<<"After exec plan"<<std::endl;
fftw_destroy_plan(plan);
dbg<<"After destroy plan"<<std::endl;
xt._dx = 2*M_PI/(_N*_dk);
dbg<<"Done transform"<<std::endl;
}
