Rotation angles

The standard loader normally reads rotation angles from the input file:

rotation_angles:
  data_path: /entry1/tomo_entry/data/rotation_angle

If this dataset is absent or unsuitable, define an evenly spaced angle array using its start, stop, and total number of angles:

 - method: standard_tomo
   module_path: httomo.data.hdf.loaders
   parameters:
     data_path: /1-TempPlugin-tomo/data
     image_key_path: /entry1/tomo_entry/instrument/detector/image_key
     rotation_angles:
       user_defined:
         start_angle: 0
         stop_angle: 180
         angles_total: 724

start_angle and stop_angle are measured in degrees. angles_total specifies how many equally spaced angles HTTomo generates.

Note

Both start_angle and stop_angle are included in the generated array. For more than one angle, the spacing in degrees is (stop_angle - start_angle) / (angles_total - 1).

For example, a limited-angle scan from -49 to 59 degrees inclusive, with a step of 0.05 degrees, contains 2161 projections:

rotation_angles:
  user_defined:
    start_angle: -49
    stop_angle: 59
    angles_total: 2161

Set angles_total to the number of projection images, excluding flat and dark frames.