ENH add moment weight sums to output

CHANGES.md

@@ -5,6 +5,7 @@
     - Added `fwhm_smooth` keyword to pre-PSF moments routines to allow for extra
       smoothing of the profile before the moments are measured.
     - Added caching of FFTs in metacal and pre-PSF moment rountines.
+    - Added moments weight function normalization.
 
 
 ## v2.0.6

mdet_tests/test_mdet_regression.py

@@ -232,7 +232,10 @@ def test_mdet_regression(fname, write=False):
     else:
         old_data = fitsio.read(fname)
         for col in old_data.dtype.names:
-            if ('psf_' in col or 'ratio' in col) and '1.3.9' in fname:
+            if (
+                ('psf_' in col or 'ratio' in col)
+                and ('1.3.9' in fname or '2.0' in fname)
+            ):
                 rtol = 1.0e-4
                 atol = 1.0e-4
             else:

ngmix/gmix/gmix.py

@@ -1239,15 +1239,13 @@ def get_weighted_moments_stats(ares):
 
     res = {}
     for n in ares.dtype.names:
-        if n == "sums":
-            res[n] = ares[n].copy()
-        elif n == "sums_cov":
+        if n in ["sums", "sums_cov"]:
             res[n] = ares[n].copy()
         else:
             res[n] = ares[n]
 
     res.update(
-        moments.make_mom_result(res["sums"], res["sums_cov"])
+        moments.make_mom_result(res["sums"], res["sums_cov"], res["wsum"])
     )
 
     return res

ngmix/moments.py

@@ -349,7 +349,7 @@ def g2mom(g1, g2, T):
     return Irr, Irc, Icc
 
 
-def make_mom_result(mom, mom_cov):
+def make_mom_result(mom, mom_cov, mom_norm=None):
     """Make a fitting results dict from a set of moments.
 
     Parameters
@@ -358,6 +358,9 @@ def make_mom_result(mom, mom_cov):
         The array of moments in the order [Mv, Mu, M1, M2, MT, MF].
     mom_cov : np.ndarray
         The array of moment covariances.
+    mom_norm : float, optional
+        The sum of the moment weight function itself. This is added to the output data.
+        The default of None puts in NaN.
 
     Returns
     -------
@@ -389,6 +392,7 @@ def make_mom_result(mom, mom_cov):
     res["flux"] = mom[mf_ind]
     res["mom"] = mom
     res["mom_cov"] = mom_cov
+    res["mom_norm"] = mom_norm if mom_norm is not None else np.nan
     res["flux_flags"] = 0
     res["flux_flagstr"] = ""
     res["T_flags"] = 0

ngmix/prepsfmom.py

@@ -160,11 +160,11 @@ def _meas(self, obs, psf_obs, return_kernels):
         tot_var = np.sum(1.0 / obs.weight[msk])
 
         # run the actual measurements and return
-        mom, mom_cov = _measure_moments_fft(
+        mom, mom_cov, mom_norm = _measure_moments_fft(
             kim, kpsf_im, tot_var, eff_pad_factor, kernels,
             im_row - psf_im_row, im_col - psf_im_col,
         )
-        res = make_mom_result(mom, mom_cov)
+        res = make_mom_result(mom, mom_cov, mom_norm)
         if res['flags'] != 0:
             logger.debug("pre-psf moments failed: %s" % res['flagstr'])
 
@@ -291,6 +291,7 @@ def _measure_moments_fft(
     fkp = kernels["fkp"]
     fkc = kernels["fkc"]
 
+    mom_norm = np.sum(kernels["fk00"].real) * df2
     mf = np.sum((kim * fkf).real) * df2
     mr = np.sum((kim * fkr).real) * df2
     mp = np.sum((kim * fkp).real) * df2
@@ -324,7 +325,7 @@ def _measure_moments_fft(
 
     mom = np.array([np.nan, np.nan, mp, mc, mr, mf])
 
-    return mom, m_cov
+    return mom, m_cov, mom_norm
 
 
 @njit
@@ -580,6 +581,7 @@ def _ksigma_kernels(
         fkc=fkc,
         msk=msk,
         nrm=nrm,
+        fk00=knrm,
     )
 
 
@@ -679,6 +681,7 @@ def _gauss_kernels(
         fkc=fkc,
         msk=msk,
         nrm=nrm,
+        fk00=knrm,
     )
 
 

ngmix/tests/test_prepsfmom.py

@@ -762,7 +762,7 @@ def test_moments_make_mom_result_flags():
     for i in range(2, 6):
         _mom_cov = mom_cov.copy()
         _mom_cov[i, i] = -1
-        res = make_mom_result(mom, _mom_cov)
+        res = make_mom_result(mom, _mom_cov, 1)
         assert (res["flags"] & ngmix.flags.NONPOS_VAR) != 0
         assert ngmix.flags.NAME_MAP[ngmix.flags.NONPOS_VAR] in res["flagstr"]
         if i == 5:
@@ -782,7 +782,7 @@ def test_moments_make_mom_result_flags():
     # neg flux
     _mom = mom.copy()
     _mom[5] = -1
-    res = make_mom_result(_mom, mom_cov)
+    res = make_mom_result(_mom, mom_cov, 1)
     assert (res["flags"] & ngmix.flags.NONPOS_FLUX) != 0
     assert ngmix.flags.NAME_MAP[ngmix.flags.NONPOS_FLUX] in res["flagstr"]
     assert res["flux_flags"] == 0
@@ -793,7 +793,7 @@ def test_moments_make_mom_result_flags():
     # neg T
     _mom = mom.copy()
     _mom[4] = -1
-    res = make_mom_result(_mom, mom_cov)
+    res = make_mom_result(_mom, mom_cov, 1)
     assert (res["flags"] & ngmix.flags.NONPOS_SIZE) != 0
     assert ngmix.flags.NAME_MAP[ngmix.flags.NONPOS_SIZE] in res["flagstr"]
     assert res["flux_flags"] == 0
@@ -806,7 +806,7 @@ def test_moments_make_mom_result_flags():
         _mom_cov = mom_cov.copy()
         _mom_cov[4, i] = np.nan
         _mom_cov[i, 4] = np.nan
-        res = make_mom_result(mom, _mom_cov)
+        res = make_mom_result(mom, _mom_cov, 1)
         assert (res["flags"] & ngmix.flags.NONPOS_SHAPE_VAR) != 0
         assert ngmix.flags.NAME_MAP[ngmix.flags.NONPOS_SHAPE_VAR] in res["flagstr"]
         assert res["flux_flags"] == 0