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Add management of `angle_offset` and `angle_range` for pcotomo

payno requested to merge fix_91 into master


Allow users to provide parameters in order to define a start_angle_offset and a angle_interval to create NXtomo split from pcotomo. If provided It will apply a subselection once the NXtomo will be created.

note: this will simply upgrade the image_control_key to INVALID


  • add NXtomo utils functions to do selections according to
    • start_angle and stop_angle (see below API first point)
    • start_angle_offsetandangle_interval` (see below API second point)
    • add unit tests
    • add documentation
  • add parameter in the HDF5Configuration file
  • apply sub-selection when requested from PCOTomoAcquisition
    • add unit tests
  • update documentation
  • test on a "real dataset"


fix #91 (closed)


NXtomo python API.

first point: add sub_select_selection_from_angle_range

function used to do a sub selection in a NXtomo according to rotation angle. Only projections will be affected. If this needs to evolve then we could provide a frame_type parameter (as a tuple) to know on which frame we should apply this selection.

To simplify (a lot) this will only affect the image_key of the NXtomo. So the detector data will stay unmodified. This is not very intuitive but way simpler.

    def sub_select_selection_from_angle_range(
        nx_tomo, start_angle: float, stop_angle: float, copy=True
        create a NXtomo like `nx_tomo` input but update `image_key_control` to INVALID for
        all projections which does not fulfill the condition: start_angle < rotation_angle < stop_angle

        Note: Darks and flat will not be affected by this sub selection

        :param float start_angle_offset: offset to apply to start the selection. Expected in degree. Must be signed.
                                         **The offset is always relative to the first projection angle value**
        :param float angle_interval: interval covered by the selection
        :param bool shift_angles: should we shift the angles of `-start_angle_offset` (once the selection is done)
        :param bool copy: if True then copy the nx_tomo

second point: add sub_select_from_angle_offset

This is the function required for #91 (closed) This is applying sub_select_selection_from_angle_range with some pre processing (determine start_angle and stop_angle) and it is also able to shift (projection) angles

    def sub_select_from_angle_offset(
        nx_tomo, start_angle_offset: float, angle_interval: float, shift_angles: bool
Edited by payno

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