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Inputs

• galaxy postage stamp image
• PSF postage stamp image
• RA/DEC/z come along for the ride

Outputs

• e1, e2, size directly come out of HSM.
• flux, I believe, is not a direct product of HSM, but we should measure this too. Easiest thing is to just sum pixels.
• RA/DEC/z

Output here is essentially the "shear catalog"

Check HSM results against input to issue #2 and issue #4 ("truth" catalog of magnifications/shears/fluxes). Initially, catalogs will effectively hold the same quantities (e.g., measured ellipticity <-> input shear), though later on when shape and size noise are added input/output catalog schemas may diverge since intrinsic shape/size are unknown to measurer.

Note that this issue should be applicable to both PhoSim generated postage stamp images and GalSim generated postage stamp images.

Making a new issue from this request by @slosar on #6:

ii) It would be good to be able to also predict point correlation functions, both 3D xi(r) (aka good old BAO xi) and projected (wp) while you are at it (I don't want to be pulling this from separate pieces).
iii) Also, the angular matter power spectra for a given window function, both the full calculation, the Limber approx and the thin slice approximation (I can find formulas). Incidentally, this is what we need to trivially do the calculating for Schlegel, so there is a lot of synergy for this...

Are the shear-shear and shear-galaxy power spectra and correlation functions calculated in this notebook using the randomfield package correct (in linear theory) ?

Same inputs as Issue #2.

Inputs (ruthlessly simple)

• flux
• shear/magnification (from to-be-extended astropy.randomfield)
• RA/DEC/z (doesn't actually affect postage stamp, but needs to be recorded)
• assume exponential
• assume zero intrinsic ellipticity
• assume fixed Gaussian PSF
• fixed intrinsic size (recommend ~0.3 arcsec half-light-radius)

We want to produce PhoSim images but to extract postage stamps of the deblended galaxies to pass to the HSM algorithm. We need approximately a full focal plane. So, we can try to separately generate the sky background and each galaxy and then cut out postage stamps of the each galaxy + the added background.

Input

delta field realization at z=0, as a 3D numpy array.

Method

Use equation (62) of Weinberg 2012:

The idea is to calculate the whole 3D field so this step is independent of where galaxies are placed.

Output

Psi(x,y,z) as a 3D numpy array.

I have been working on shape measurements for weak lensing. The above shows the comparison among re-Gauss(x), BJ(+) and my new try(red dots). I have an older pipeline based on BJ02 and Hirata & Seljak 2003, I did not add that one. Just want to see if the new method works or not.

The psf is Kolgomorov with FWHM=0.7 and e1=0.04,e2=0.03.
Galaxy catalog is from fastcat, with simply exponential profile.
pixel size -0.2"/pix

I will do some further test.

Create an annotated sequence of commands to perform a complete trip. Ideally this should start from scratch and include the commands needed to install fastcat, etc.

Inputs (ruthlessly simple)

• flux
• shear/magnification (from to-be-extended astropy.randomfield)
• RA/DEC/z (doesn't actually affect postage stamp, but needs to be recorded)
• assume exponential
• assume zero intrinsic ellipticity
• assume fixed Gaussian PSF
• fixed intrinsic size (recommend ~0.3 arcsec half-light-radius)

Outputs

• a ~24x24ish galaxy postage stamp image
• PSF (image).
• RA/DEC/z (initially just passes straight through so can be used in eventual shape catalog, though, ultimately, these will be inferred from the data)

After first round trip, we can add shape noise, size noise, etc.

The goal is to calculate the theory prediction for the thing that we estimate from the data. We already have a tabulated linear theory P(k). Is there already a relatively standalone piece of code to do this?

This will need to go into CosmoSIS.

Will start with Athena.

Since we now have completed the chain from fastcat output to GalSim images to HSM shapes, we are ready to compare these input (from fastcat) and output (from HSM) catalogs.

Input is either numpy arrays or HDF5 file. Work from delta field at z=0 or light-cone physical density field?

The initial plan is to use CosmoSIS and turn off any CMB, etc, priors so we can directly compare with the fixed input parameters.

Add something (labeled plot, table, ...) here to summarize today's progress on issues:

• Chris #4
• David #5
• Mathew #8
• Wentao #9
• Javier #10
• Aaron #11
• Pat #12

Currently Javier gives me a covmat from Athena (which uses some kind of jacknife). How should we go about making a covmat for output from TreeCorr?