In Qxy include masking, calculating errors and gravity

[Steve Williams]

From discussion with Richard Heenan, initally use the errors from the input workspace and propogation of errors.

Gravity correction needs to be an option to the algorithm, I'll use the same formula as from Q1D.

[Steve Williams]

The error calculation is straight forward, the proportional error on the counts remains as for the input workspace before they are summed into the Q bins. 2 hours

I'd like to put the gravity correction into a new MatrixWorkspace::detectorTwoTheta(det, double) method that only works one workspaces whose units are wavelength and takes account of gravity. 2 hours

Adding the masking, looking at Q1D this shouldn't take a significant amount of time.

Adding more tests 2 hours

total 6 hours

[Martyn Gigg]

Time estimate, M. Gigg: 6 hours seems like a reasonable time frame. I have one comment about the detectorTwoTheta calculation. It seems to me that we only need one method on the workspace but it should just take 2 arguments: The detector and a boolean flagging whether gravity should be taken into account.

[Steve Williams]

(In [8007]) MatrixWorkspace has a new method to calculate the gravitational fall of a neutron. There is a new helper class with functionality to include gravitational corrections in calculations of Q re #2004

[Steve Williams]

There should be a new property on Qxy, AccountForGravity. For most input workspaces (must be in units of wave length) the result is similar with and without gravity

[Nick Draper]

Bulk move of tickets to iteration 27, if your ticket is essential for Iteration 26 then move it back.

[Nick Draper]

Sorry I didn't mean to move these ones reverting back to It 26

[Michael Whitty]

yes, this seems to work. difference is quite evident.

[Stuart Campbell]

This ticket has been transferred to github issue ​2851