LoadSQW: transform the coordinates from Q to the scaled 'hkl'

[mantid-builder]

This issue was originally TRAC 4846

Original Reporter: @jzikovsky

This ticket is blocked by :

• TRAC4813

Alex says: "When Andrei finishes his thicket on transformation matrix (http://trac.mantidproject.org/mantid/ticket/4813), changes and coordinate system scaling should be added to LoadSQW algorithm. "

Basically scale the axes so that a peak at H=1 is at a position of (1,0,0) on the axes. Changes the UNITS of the axes to something like 2.18 Ang^-1^.

[mantid-builder]

@abuts (2012-02-22T17:43:58):
User who loads sqw would expect to see the same image as he was observing when using Horace.

Horace currently writes momentum and energies in crystal frame, momentums in reverse A (see Units in Mantid), energies in mEv and also stores image, which is obtained from these (events) by an affine transformation. The transformation involves rotation and scaling to (almost) arbitrary units (scalable) The stored events are aligned with the image even if the image is not aligned with crystal orthogonal system (e.g. if the image's X-axis is along direction [1,1,0] and has limits -1,+1, these limits are applied to the projection of Q in crystal sytem on the axis [1,1,0]

The transformation is stored alongside with image.
I am not sure, if it is direct or reverse transformation (QdE->image or image->QdE).

As Andrei works on creating and storing transformation, which would convert Q themselves into some non-axis aligned coordinate system,
the idea of the ticket is to read Horace transformation and use it when reading events transforming them into the system where they belong.

When image is axis aligned, related to cubic lattice and in reverse lattice units, the transformation is reduced to the one, mentioned above.

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@NickDraper (2012-04-30T14:15:50):
Moved at end of release 2.1

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@jzikovsky (2012-05-14T16:11:19):
Andrei, you can probably handle this request since you're more familiar with the whole axis units business...

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@NickDraper (2012-08-10T12:45:13):
http://www.mantidproject.org/Release_Notes_2_2_Full_List

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@NickDraper (2012-10-28T11:42:52):
Moved to release 2.4

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@NickDraper (2013-01-28T09:23:33):
Moved at the code freeze for release 2.4

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@NickDraper (2013-07-26T13:59:10):
Moved to the Backlog after the code freeze for R2.6

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@abuts (2013-09-25T15:43:44):
(In http://trac.mantidproject.org/mantid/ticket/5226) Load algorithm should be able to recognize sqw file (e.g. AutoTestData/test_horace_reader.sqw) , invoke LoadSQW interface and load sqw file properly.

Worth checking if it properly recognizes .SQW extension on Unix (it is somewhere in file helper and related to it so a person well familiar with this helper can give answer directly)

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@NickDraper (2014-02-14T11:07:57):
bulk move to assigned at the into of the triage step

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