3D Instrument View: improve startup performance for large instruments.

[Janik Zikovsky]

It takes a couple of seconds event on a fast computer to build up the color list for all pixels on e.g. TOPAZ. Perhaps parallelization is the way to make it faster, or maybe re-work the way colors get passed down.

[Janik Zikovsky]

As an add-on, consider how integrating the colors takes time...

[Janik Zikovsky]

Here is the timing for the WISH instrument (WISH00016748 file) before any changes:

Instrument3DWidget::ParseInstrumentGeometry() took 0.294798 seconds Instrument3DWidget::calculateBinRange() took 19.0522 seconds Instrument3DWidget::calculateColorCounts(): mInstrumentActor->getDetectorIDList() took 0.277472 seconds Instrument3DWidget::createWorkspaceIndexList() took 0.744245 seconds Instrument3DWidget::calculateColorCounts():Integrating workspace took 39.0107 seconds

1281 GL 1d error1

Instrument3DWidget::calculateColorCounts(): mInstrumentActor->setDetectorColors() took 0.034032 seconds Instrument3DWidget::calculateColorCounts() took 40.2688 seconds Instrument3DWidget::setWorkspace() took 59.6285 seconds

It can be seen that getting the bin range and calculating the color counts are, by far, the slowest operations and are the first spots to optimize.

[Janik Zikovsky]

Timing for SNAP_4105:

Instrument3DWidget::ParseInstrumentGeometry() took 0.011403 seconds Instrument3DWidget::calculateBinRange() took 0.101935 seconds Instrument3DWidget::calculateColorCounts(): mInstrumentActor->getDetectorIDList() took 0.29363 seconds

Instrument3DWidget::createWorkspaceIndexList() took 3.34379 seconds Instrument3DWidget::calculateColorCounts():Integrating workspace took 4.74109 seconds Instrument3DWidget::calculateColorCounts(): mInstrumentActor->setDetectorColors() took 0.051766 seconds

Instrument3DWidget::calculateColorCounts() took 11.0607 seconds Instrument3DWidget::setWorkspace() took 11.2118 seconds

[Janik Zikovsky]

(In [7625]) Refs #1872: Added an option to use the 'entire range' in X in the instrument view by default. This saves about 20 seconds when opening the WISH instrument view: 59 seconds is down to 40 seconds opening time.

[Janik Zikovsky]

(In [7626]) Refs #1872: Had left on some timing output.

[Janik Zikovsky]

My upcoming check in timing results, for the part of the calculation to integrate the counts (the slowest part):

File SNAP_4111, EventWorkspace.

As a pseudo-workspace 2D, binned to 1600 bins: Non parallelized: 47 seconds after sorting event list.

As a pseudo-workspace 2D, binned to 16000 bins: Non parallelized: 401 seconds after sorting event list.

As an event workspace: Non-parallelized: 30 seconds. Parallelized, first run: 5.5 seconds. Parallelized, second run: 0.3 seconds.

So the speed improvement is easily x100 times, up to x1000 times for very finely binned workspaces!

[Janik Zikovsky]

(formatting fix)

My upcoming check in timing results, for the part of the calculation to integrate the counts (the slowest part):

File SNAP_4111, EventWorkspace.

As a pseudo-workspace 2D, binned to 1600 bins:

• Non parallelized: 47 seconds after sorting event list.

As a pseudo-workspace 2D, binned to 16000 bins:

• Non parallelized: 401 seconds after sorting event list.

As an event workspace:

• Non-parallelized: 30 seconds.
• Parallelized, first run: 5.5 seconds.
• Parallelized, second run: 0.3 seconds.

So the speed improvement is easily x100 times, up to x1000 times for very finely binned workspaces!

[Janik Zikovsky]

(In [7654]) Refs #1872: 100x to 1000x faster integration of counts for the purposes of instrument display. Is done in parallel and can take advantage of EventList properties to make it faster.

[Janik Zikovsky]

Next up:

Instrument3DWidget::calculateColorCounts(): mInstrumentActor->getDetectorIDList() took 2.7619 seconds

and

Instrument3DWidget::createWorkspaceIndexList() took 3.47304 seconds

... these two are the slowest steps now.

[Janik Zikovsky]

(In [7655]) Refs #1872: the integration code does not sort by TOF if it doesn't need to = 0.08 seconds instead of 30! Also, removing timing output.

[Janik Zikovsky]

(In [7692]) Refs #1872: The workspace index list is now cached in the 3D instrument widget, saving ~ 3 seconds per call. Pick detector now is a hundred times more responsive on large instruments.

[Janik Zikovsky]

(In [7693]) Fixes #1872: performance is much better.

[Michael Whitty]

indeed, performance is much improved. Testing with TOPAZ, pick completely fails pre these changes, and works well in recent builds.

[Stuart Campbell]

This ticket has been transferred to github issue ​2719