sinusoidal_trajectory_2d_fan#

diffct.geometry.sinusoidal_trajectory_2d_fan(n_views, sid, sdd, amplitude=50.0, frequency=2.0, start_angle=0.0, device='cuda', dtype=torch.float32)[source]#

Generate sinusoidal trajectory geometry for 2D fan-beam CT.

Creates a trajectory where the source follows a sinusoidal path, with radial oscillations as it rotates around the origin.

Parameters:

  • n_views (int) – Number of projection views.

  • sid (float) – Mean Source-to-Isocenter Distance (SID), in physical units.

  • sdd (float) – Source-to-Detector Distance (SDD), in physical units.

  • amplitude (float, optional) – Amplitude of sinusoidal radial variation (default: 50.0).

  • frequency (float, optional) – Number of oscillation cycles per full rotation (default: 2.0).

  • start_angle (float, optional) – Starting angle in radians (default: 0.0).

  • device (str or torch.device, optional) – Device for tensors (default: ‘cuda’).

  • dtype (torch.dtype, optional) – Data type for tensors (default: torch.float32).

Returns:

  • src_pos (torch.Tensor) – Source positions, shape (n_views, 2).

  • det_center (torch.Tensor) – Detector center positions, shape (n_views, 2).

  • det_u_vec (torch.Tensor) – Detector u-direction unit vectors, shape (n_views, 2).

Examples

>>> src_pos, det_center, det_u_vec = sinusoidal_trajectory_2d_fan(
...     n_views=360, sid=1000.0, sdd=1500.0, amplitude=100.0, frequency=3.0
... )