Incorrect representation after ConvertToMDEvents for reduced Q range.

[Stuart Campbell]

If you run convertToMDEvents for an inelastic dataset for a Q-range that is smaller than the maximum Q value in the dataset then you get a strange display. Basically the higher Q values are wrapped around and mapped onto low Q bins/boxes.

Procedure used:

• Load CNCS_7860_event.nxs from AutoTestData directory.
• AddSampleLog to add Ei of 3.0 (Number) to workspace.
• ConvertToMDEvents (see screenshot for parameters)

For the second case I just changed the first number for MaxValues to 4.

[Stuart Campbell]

One thing to note, that if I run binMD on the workspace that looks wrong (0<Q<2.0), then it looks correct again. So I don't know if the problem is with the box structure of the MDEventWorkspace.

[Janik Zikovsky]

My guess at what is going on:

• If you use addEvent() to add a single event to the parent IMDBox, there is NO bounds checking. This is for performance. So the events on the right side of the plot end up mis-placed in the left as they overflow the X dimension.
• The answer is to use the addEvents() method on IMDBox, which does do bounds checking. Or to do your own bounds checking before if you prefer.

[Alex Buts]

refs #4550 Stupid error in conversion fixed

Changeset: 1cfe1a849f4e37a474ada1e52ef23108aefb2d19

[Alex Buts]

That was really stupid error in the code during bound checking in this place. Accordingly, difficult to spot.

Hope it has gone now.

[Stuart Campbell]

Looks good.

[Stuart Campbell]

This ticket has been transferred to github issue ​5397