from typing import List, Tuple
from numpy import arctan, arctan2, dtype, floating, hypot, linspace, meshgrid, ndarray
def _relative_position_meshgrid(
frame_shape: Tuple[int, int],
beam_center: Tuple[float, float],
pixel_sizes: Tuple[float, float],
) -> List[ndarray]:
return meshgrid(
linspace(
(0.5 - beam_center[1]) * pixel_sizes[1],
(frame_shape[1] - 0.5 - beam_center[1]) * pixel_sizes[1],
frame_shape[1],
),
linspace(
(0.5 - beam_center[0]) * pixel_sizes[0],
(frame_shape[0] - 0.5 - beam_center[0]) * pixel_sizes[0],
frame_shape[0],
),
)
[docs]
def scattering_angles(
frame_shape: Tuple[int, int],
beam_center: Tuple[float, float],
pixel_sizes: Tuple[float, float],
distance: float,
) -> ndarray[Tuple[int, int], dtype[floating]]:
"""Computes the angles of pixels from the sample for a given geometry.
Args:
frame_shape: The shape of a frame.
beam_center: The center position of the beam in pixels.
pixel_sizes: The real space size of a detector pixel.
distance: The distance between the detector and the sample.
Returns:
An array of pixel angles from the sample.
"""
yy, xx = _relative_position_meshgrid(frame_shape, beam_center, pixel_sizes)
return arctan(hypot(xx, yy) / distance)
[docs]
def azimuthal_angles(
frame_shape: Tuple[int, int],
beam_center: Tuple[float, float],
pixel_sizes: Tuple[float, float],
) -> ndarray[Tuple[int, int], dtype[floating]]:
"""Computes the azimuthal angles of pixels from the beam center.
Args:
frame_shape: The shape of the frame.
beam_center: The center position of the beam in pixels.
Returns:
An array of pixel azimuthal angles from the beam center.
"""
yy, xx = _relative_position_meshgrid(frame_shape, beam_center, pixel_sizes)
return arctan2(xx, yy)
