void Transformer::init() {
//printf("num_threads = %d\n", omp_get_max_threads());
printf("nthreads = %d\n", nfft_get_num_threads());
/* init */
fftw_init_threads();
fftw_plan_with_nthreads(omp_get_max_threads());
/* precomputation (for fast polynomial transform) */
nfsft_precompute(N, 1000.0, 0U, 0U);
/* Initialize transform plan using the guru interface. All input and output
* arrays are allocated by nfsft_init_guru(). Computations are performed with
* respect to L^2-normalized spherical harmonics Y_k^n. The array of spherical
* Fourier coefficients is preserved during transformations. The NFFT uses a
* cut-off parameter m = 6. See the NFFT 3 manual for details.
*/
nfsft_init(&plan, N, M);
//nfsft_init_guru(&plan, N, M, NFSFT_MALLOC_X | NFSFT_MALLOC_F |
// NFSFT_MALLOC_F_HAT | NFSFT_NORMALIZED | NFSFT_PRESERVE_F_HAT,
// PRE_PHI_HUT | PRE_PSI | FFTW_INIT | FFT_OUT_OF_PLACE, 6);
}
static PyObject *nfft(PyObject *self, PyObject *args, PyObject *kwargs)
{
PyObject *in_obj, *coord_obj;
static char *kwlist[] = {"real_space", "coordinates", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "OO", kwlist, &in_obj, &coord_obj)) {
return NULL;
}
PyObject *coord_array = PyArray_FROM_OTF(coord_obj, NPY_DOUBLE, NPY_IN_ARRAY);
PyObject *in_array = PyArray_FROM_OTF(in_obj, NPY_COMPLEX128, NPY_IN_ARRAY);
if (coord_array == NULL || in_array == NULL) {
Py_XDECREF(coord_array);
Py_XDECREF(in_array);
return NULL;
}
int ndim = PyArray_NDIM(in_array);
if (ndim <= 0) {
PyErr_SetString(PyExc_ValueError, "Input array can't be 0 dimensional\n");
return NULL;
}
if ((PyArray_NDIM(coord_array) != 2 || PyArray_DIM(coord_array, 1) != ndim) && (ndim != 1 || PyArray_NDIM(coord_array) != 1)) {
PyErr_SetString(PyExc_ValueError, "Coordinates must be given as array of dimensions [NUMBER_OF_POINTS, NUMBER_OF_DIMENSIONS] of [NUMBER_OF_POINTS for 1D transforms.\n");
Py_XDECREF(coord_array);
Py_XDECREF(in_array);
return NULL;
}
int number_of_points = (int) PyArray_DIM(coord_array, 0);
nfft_plan my_plan;
int total_number_of_pixels = 1;
int dims[ndim];
int dim;
for (dim = 0; dim < ndim; ++dim) {
dims[dim] = (int)PyArray_DIM(in_array, dim);
total_number_of_pixels *= dims[dim];
}
#if defined(ENABLE_THREADS)
printf("OMP_NUM_THREADS=%s\n",getenv("OMP_NUM_THREADS"));
printf("nthreads = %d\n", nfft_get_num_threads());
fftw_init_threads();
#endif
nfft_init(&my_plan, ndim, dims, number_of_points);
memcpy(my_plan.f_hat, PyArray_DATA(in_array), total_number_of_pixels*sizeof(fftw_complex));
memcpy(my_plan.x, PyArray_DATA(coord_array), ndim*number_of_points*sizeof(double));
if (my_plan.nfft_flags &PRE_PSI) {
nfft_precompute_one_psi(&my_plan);
}
nfft_trafo(&my_plan);
int out_dim[] = {number_of_points};
PyObject *out_array = (PyObject *)PyArray_FromDims(1, out_dim, NPY_COMPLEX128);
memcpy(PyArray_DATA(out_array), my_plan.f, number_of_points*sizeof(fftw_complex));
// Clean up memory
nfft_finalize(&my_plan);
#if defined(ENABLE_THREADS)
fftw_cleanup_threads();
#endif
Py_XDECREF(coord_array);
Py_XDECREF(in_array);
return out_array;
}
