Compute a CIC density field from galaxy catalog

[EiffL]

This issue to add a functionality to compute a 3d CIC mesh from a galaxy catalog, from which we can then try to compute the power spectrum.
@modichirag Do you want to take care of that? Essentially, this would involve using FlowPM to CIC paint a galaxy density field from a galaxy catalog

[EiffL]

Hum.... so I guess we already have this: https://github.com/DifferentiableUniverseInitiative/DHOD/blob/master/diffhod/experimental/nn/utils/tools.py

Should we use that or should we use flowpm tools instead?

[EiffL]

oh wow, no sorry that's numpy code.

[modichirag]

Yeah, I will look into it. There is TF CIC and readout code in flowpm/tools. But the one in MeshTF is tricky to parse for either, and writing a higher level function to go along with it has been on my to-do-list for a while.

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On Fri, Apr 3, 2020 at 9:57 AM Francois Lanusse ***@***.***> wrote: oh wow, no sorry that's numpy code. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#18 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADF45XRFWOJIVRDPPEF3SK3RKYIPTANCNFSM4L4IK5YQ> .

-- Chirag Modi Sixth Year Graduate PhD. Physics UC Berkeley

[EiffL]

Great :-D
I took a stab at it here, check it out: https://github.com/DifferentiableUniverseInitiative/DHOD/blob/u/EiffL/FlowPM/nb/PowerSpectrum.ipynb

This relies on this update of flowpm to make it nicely TF2 compliant: https://github.com/modichirag/flowpm/pull/43

[EiffL]

Prototype is now working over there: https://github.com/DifferentiableUniverseInitiative/DHOD/blob/u/EiffL/FlowPM/nb/PowerSpectrum.ipynb
Not only does it computes a CIC field of a galaxy catalog, but also does the optimization.

I think this is working fine now, and we don't really need any other things than the cic painting tools in FlowPM. So I'm gonna say that this is pretty much done, and is just waiting on modichirag/flowpm#43

[EiffL]

I think this is done.... what cic painting function are you using in practice @bhorowitz ?

[EiffL]

We now have a cic painting code directly in the utils folder