Add transformations

TODO

• add NXtransformations
  • add NXTransformations class and utils
  • replace flip_lr and flip_ud dataset by standard NXTranslations -> for the large part of this pr remove it but it would be better if we can keep some compatibility for some time
  • update rotation_angle, x_translation, y_translation, z_translation ? -> lets go one step at the time
  • add an example on how to add Transformation to an NXdetector from a script (and limitations)
  • when dump to disk; for the Transformation without dependencies add dependence on gravity
  • integrate to nabu -> nabu#418 (closed)
  • integrate to tomwer -> tomwer#967

TRANSFORMATIONS and NXsample

Today NXtomo documentation does not present any link to NXtransformations when NXsample does and recommand to use them. Which is confusing for the less.

Anyway for tomography {x,y,z}_translation and rotation_angle are convenient to have and we don't want to remove them. rotation_angle is even mandatory.

So what could be done is to generate NXtransformations group but based from other dataset values. This would prevent any conflict and make it more 'nexus' compliant. Else we keep this to the NXdetector which is necessary to store 'flip' l/r and u/d information

related to

• tomoscan!145 (merged)
• nabu!316 (closed)

screenshots

results on a real use case output of h52nx (getting one 'x flip (lr_flip)')

wout explanation of NXtransformations