Fixed window function math for tapering function #84
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the |
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Out of curiosity, what do you need from |
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Right now we have something that returns Omega_pp(\nu_i) ~ \int A^2 (\nu_i) dOmega. Turns out we'll need Omega_pp(\nu_i, \nu_j) ~ \int A(\nu_i) A(\nu_j) dOmega as well. |
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What does the i & j index? different antennas, frequencies, or something else? |
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Different frequencies. |
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Ok, just pushed. Hopefully this time it's a little less buggy. I mentioned to @nkern today that in working through this, I realized that the pspec scalar normalization infrastructure is not currently able to accommodate non-trivial tapers + non-trivial weighting matrices simultaneously. Details in the notes that I've attached, which will be posted to the HERA memo series. There is a hacky way to do this, involving assigning half (i.e., the square root) of the weighting matrix to Q and having another square root of the weight act on the data. But this is beginning to feel like epicycles upon epicycles, so if there is a need to push further along this direction I'm ripping out the old stuff and implementing Q "properly" (i.e., I'll subclass and make a version where Q is truly equal to dC/dp). Notes here: main.pdf |
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@acliu On p6 of your note, should I read an "and" between the bullet points below Eq. 31, or an "or"? In light of this, should we raise a warning when |
| @@ -681,6 +685,75 @@ def get_G(self, key1, key2): | |||
| G[i,j] += np.einsum('ab,ba', iR1Q[i], iR2Q[j]) | |||
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| return G / 2. | |||
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| def get_H(self, key1, key2, taper='none'): | |||
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I don't see H_ab defined anywhere in the note?
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Actually, it's there. Equation 33. Unfortunate page break location makes it hard to see.
hera_pspec/pspecdata.py
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| (See HERA memo #44). As currently implemented, this approximates the | ||
| primary beam as frequency independent. Under this approximation, the | ||
| our H_ab is defined using the equation above *except* we have | ||
| Q^{yet_another} rather than Q_b, where |
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yet_another is not a great name for a variable...
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Changed it to Q^{tapered}
hera_pspec/pspecdata.py
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| M = np.linalg.pinv(G, rcond=1e-12) | ||
| #U,S,V = np.linalg.svd(F) | ||
| #M = np.einsum('ij,j,jk', V.T, 1./S, U.T) | ||
| raise NotImplementedError |
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Please say what's not implemented, e.g. NoteImplementedError("G^-1 mode not currently supported.")
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(OK, I now see that you do raise warnings about this.) |
This fixes the window functions to account for tapering. Currently it assumes a frequency-independent primary beam, but fixing this will require some changes to pyuvdata that haven't been implemented yet.