Nebula initialization: adaptive second moments followed by some EM

davidwhogg / LensTractor

finding strong gravitationally lensed quasars in ground-based data

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Nebula initialization: adaptive second moments followed by some EM #49

Open aagnello opened 9 years ago

aagnello commented 9 years ago

Actions:

compute second moments in each cutout, weigh by cutout's S/N
put down two pt.sources with equal magnitude such that the overall second mom't matches the one above
go!
for Nebula4, take the residual from Nebula2 and play the same trick as above
go! Assignees: @aagnello, @drphilmarshall

aagnello commented 9 years ago

We didn't get to this, because we are still debugging H1413 using manual Nebula init. Let's come back to it soon though.

drphilmarshall commented 9 years ago

@aagnello I believe you have something to report on how this is going, based on your algorithm development in Mathematica. (BTW is there any way you can check your Mathematica work in? It's currently outside of version control which is bad.) You might need to make some additional issues to subtask the work of coding this advanced initialization into LT.

drphilmarshall commented 9 years ago

From discussions with @aagnello it seems that the way to go is to subclass the tractor and give it some quick and dirty initialization functionality that is specific to our LT problem. Let's rename this issue and make a to do list.

drphilmarshall commented 9 years ago

To do:

[x] Subclass the tractor
[ ] Build in getSecondMoments and EMoptimize methods
[x] Use this new tractor in the driver script
[ ] Implement algorithm from Mathematica in tractor-flavored python (@aagnello)
[ ] Test.