// Forward: from image to kspace
static void nufft_apply(const void* _data, complex float* dst, const complex float* src)
{
struct nufft_data* data = (struct nufft_data*)_data;
assert(!data->conf.toeplitz); // if toeplitz linphase has no roll, so would need to be added
unsigned int ND = data->N + 3;
md_zmul2(ND, data->cml_dims, data->cml_strs, data->grid, data->cim_strs, src, data->lph_strs, data->linphase);
linop_forward(data->fft_op, ND, data->cml_dims, data->grid, ND, data->cml_dims, data->grid);
md_zmul2(ND, data->cml_dims, data->cml_strs, data->grid, data->cml_strs, data->grid, data->img_strs, data->fftmod);
md_clear(ND, data->ksp_dims, dst, CFL_SIZE);
complex float* gridX = md_alloc(data->N, data->cm2_dims, CFL_SIZE);
long factors[data->N];
for (unsigned int i = 0; i < data->N; i++)
factors[i] = ((data->img_dims[i] > 1) && (i < 3)) ? 2 : 1;
md_recompose(data->N, factors, data->cm2_dims, gridX, data->cml_dims, data->grid, CFL_SIZE);
grid2H(2., data->width, data->beta, ND, data->trj_dims, data->traj, data->ksp_dims, dst, data->cm2_dims, gridX);
md_free(gridX);
if (NULL != data->weights)
md_zmul2(data->N, data->ksp_dims, data->ksp_strs, dst, data->ksp_strs, dst, data->wgh_strs, data->weights);
}
static void unisoftthresh_apply(const operator_data_t* _data, float mu, complex float* dst, const complex float* src)
{
const auto data = CAST_DOWN(thresh_s, _data);
if (0. == mu) {
md_copy(data->D, data->dim, dst, src, CFL_SIZE);
} else {
const long* transform_dims = linop_codomain(data->unitary_op)->dims;
const long* transform_strs = linop_codomain(data->unitary_op)->strs;
complex float* tmp = md_alloc_sameplace(data->D, transform_dims, CFL_SIZE, dst);
linop_forward(data->unitary_op, data->D, transform_dims, tmp, data->D, data->dim, src);
complex float* tmp_norm = md_alloc_sameplace(data->D, data->norm_dim, CFL_SIZE, dst);
md_zsoftthresh_core2(data->D, transform_dims, data->lambda * mu, data->flags, tmp_norm, transform_strs, tmp, transform_strs, tmp);
md_free(tmp_norm);
linop_adjoint(data->unitary_op, data->D, data->dim, dst, data->D, transform_dims, tmp);
md_free(tmp);
}
}
/**
* Undersampled FFT forward operator
*/
void ufft_apply(const linop_data_t* _data, complex float* dst, const complex float* src)
{
const struct ufft_data* data = CONTAINER_OF(_data, const struct ufft_data, base);
linop_forward(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, src);
md_zmul2(DIMS, data->ksp_dims, data->ksp_strs, dst, data->ksp_strs, dst, data->pat_strs, data->pat);
}
/**
* Undersampled FFT forward operator
*/
void ufft_apply(const linop_data_t* _data, complex float* dst, const complex float* src)
{
struct ufft_data* data = CAST_DOWN(ufft_data, _data);
linop_forward(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, src);
md_zmul2(DIMS, data->ksp_dims, data->ksp_strs, dst, data->ksp_strs, dst, data->pat_strs, data->pat);
}
static void toeplitz_mult(const struct nufft_data* data, complex float* dst, const complex float* src)
{
unsigned int ND = data->N + 3;
md_zmul2(ND, data->cml_dims, data->cml_strs, data->grid, data->cim_strs, src, data->lph_strs, data->linphase);
linop_forward(data->fft_op, ND, data->cml_dims, data->grid, ND, data->cml_dims, data->grid);
md_zmul2(ND, data->cml_dims, data->cml_strs, data->grid, data->cml_strs, data->grid, data->psf_strs, data->psf);
linop_adjoint(data->fft_op, ND, data->cml_dims, data->grid, ND, data->cml_dims, data->grid);
md_clear(ND, data->cim_dims, dst, CFL_SIZE);
md_zfmacc2(ND, data->cml_dims, data->cim_strs, dst, data->cml_strs, data->grid, data->lph_strs, data->linphase);
}
/**
* 1/2 || Ax - b ||^2 + rho/2 || x - y ||^2
*
* x = (ATA + lI)^-1 b
*
* X = 1 / (pat^2 + l) B
*
*/
static void ufft_apply_pinverse(const linop_data_t* _data, float rho, complex float* dst, const complex float* src)
{
const struct ufft_data* data = CONTAINER_OF(_data, const struct ufft_data, base);
md_zsadd(DIMS, data->pat_dims, data->pat, data->pat, rho);
linop_forward(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, src);
md_zdiv2(DIMS, data->ksp_dims, data->ksp_strs, dst, data->ksp_strs, dst, data->pat_strs, data->pat);
linop_adjoint(data->fft_op, DIMS, data->ksp_dims, dst, DIMS, data->ksp_dims, dst);
md_zsadd(DIMS, data->pat_dims, data->pat, data->pat, -rho);
}
static void nufft_precond_apply(const operator_data_t* _data, unsigned int M, void* args[M])
{
assert(2 == M);
const auto data = CAST_DOWN(nufft_precond_data, _data);
complex float* dst = args[0];
const complex float* src = args[1];
linop_forward(data->fft_op, data->N, data->cim_dims, dst, data->N, data->cim_dims, src);
md_zdiv2(data->N, data->cim_dims, data->cim_strs, dst, data->cim_strs, dst, data->pre_strs, data->pre);
linop_adjoint(data->fft_op, data->N, data->cim_dims, dst, data->N, data->cim_dims, dst);
}