2017_04_07 visualization meeting

Bluejeans: 107541143
UIUC people connect separately (@jjt will connect remotely)


  • UIUC issues (short term to-do list).
  • Rafts will arrive at SLAC soon.
  • Summer (and longer) plans.


  • The first engineering test raft is at SLAC and is being checked out. Engineering CCDs have flaws, but are useful for debugging.
  • It would be useful to display the Firefly version, the same way the UIUC code version is displayed (in the upper left corner of the viewer window). This is possible, but I missed how to do it. (@tatianag, can you help here?)
  • There is an issue with licensing of graphic libraries (National laps are not eligible for educational discounts), so Firefly is (at least for SLAC) changing to plotlib.

@tatianag, @xiuqin,

We (UIUC) read the cursor coordinates via the API. It is also possible to read the pixel value? We’d like our FE code to access it.


Yes, you can read pixel (flux) value the same way you are reading cursor coordinates. Just be aware that flux value is only available when mouse stops moving.

The flux value is in ReadoutCntlr.ReadoutData action payload, the exact field is action.payload.readoutItems.nobandFlux.value if it’s not 3-color image.

The flux value is not populated on every mouse move, only when mouse stops. If you are only interested in the flux value, check for

action.payload.hasValues && (action.payload.readoutItems.nobandFlux.value !== undefined)

See onReadoutData callback in firefly/demo/ffapi-2images.html example.

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