Merge c1f8de5 into e5af080

doc/changes.rst

@@ -5,6 +5,7 @@ desitarget Change Log
 0.23.1 (unreleased)
 -------------------
 
+* Set ``NUMOBS`` for LRGs in MTL using target bits instead of magnitude [`PR #345`_].
 * Update GFA targets [`PR #342`_]:
     * Handle reading Gaia from sweeps as well as matching. Default to *not* matching.
     * Makes Gaia matching radius stricter to return only the best Gaia objects.
@@ -13,16 +14,17 @@ desitarget Change Log
     * Add Gaia epoch to the GFA file header (still needs passed from the sweeps).
 
 .. _`PR #342`: https://github.com/desihub/desitarget/pull/342
+.. _`PR #345`: https://github.com/desihub/desitarget/pull/345
 
 0.23.0 (2018-08-09)
 -------------------
 
 Includes non-backwards compatible changes to standard star bit names.
 
+* STD/STD_FSTAR -> STD_FAINT, with corresponding fixes for mocks [`PR #341`_].
 * Match sweeps to Gaia and write new sweeps with Gaia columns [`PR #340`_]:
-   * Also add BRIGHTSTARINBLOB (if available) to target output files.
+   * Also add ``BRIGHTSTARINBLOB`` (if available) to target output files.
    * And include a flag to call STD star cuts function without Gaia columns.
-* STD/STD_FSTAR -> STD_FAINT, with corresponding fixes for mocks [`PR #341`_].
 
 .. _`PR #340`: https://github.com/desihub/desitarget/pull/340
 .. _`PR #341`: https://github.com/desihub/desitarget/pull/341

py/desitarget/targets.py

@@ -420,18 +420,20 @@ def calc_numobs(targets):
 
     Args:
         targets: numpy structured array or astropy Table of targets, including
-            columns DESI_TARGET, DECAM_FLUX, and DECAM_MW_TRANSMISSION
+            columns `DESI_TARGET`, `BGS_TARGET` or `MWS_TARGET`
 
     Returns:
         array of integers of requested number of observations
 
     Notes:
-        if ZFLUX or (DECAM_FLUX and DECAM_MW_TRANSMISSION) are in targets,
-            then LRG numobs depends upon zmag, else defaults to 2
-        This is NUMOBS desired before any spectroscopic observations; i.e.
+        This is `NUMOBS` desired before any spectroscopic observations; i.e.
             it does *not* take redshift into consideration (which is relevant
             for interpreting low-z vs high-z QSOs)
     """
+    #ADM set up the default logger
+    from desiutil.log import get_logger
+    log = get_logger()
+
     # Default is one observation
     nobs = np.ones(len(targets), dtype='i4')
 
@@ -449,24 +451,26 @@ def calc_numobs(targets):
     if n_no_target_class > 0:
         raise ValueError('WARNING: {:d} rows in targets.calc_numobs have no target class'.format(n_no_target_class))
 
-    #- LRGs get 1, 2, or 3 observations depending upon magnitude
-    zflux = None
-    if 'ZFLUX' in targets.dtype.names:
-        zflux = targets['ZFLUX']
-    elif 'DECAM_FLUX' in targets.dtype.names:
-        if 'DECAM_MW_TRANSMISSION' in targets.dtype.names:
-            zflux = targets['DECAM_FLUX'][:,4] / targets['DECAM_MW_TRANSMISSION'][:,4]
-        else:
-            zflux = targets['DECAM_FLUX'][:,4]
-
+    #- LRGs get 1, 2, or (perhaps) 3 observations depending upon magnitude
+    #ADM set this using the LRG_1PASS/2PASS and maybe even 3PASS bits
     islrg = (targets['DESI_TARGET'] & desi_mask.LRG) != 0
-    if zflux is not None:
-        lrg2 = islrg & (zflux < 10**((22.5-20.36)/2.5))
-        lrg3 = islrg & (zflux < 10**((22.5-20.56)/2.5))
+    #ADM default to 2 passes for LRGs
+    nobs[islrg] = 2
+    #ADM for redundancy in case the defaults change, explicitly set
+    #ADM NOBS for 1PASS and 2PASS LRGs
+    try:
+        lrg1 = (targets['DESI_TARGET'] & desi_mask.LRG_1PASS) != 0
+        lrg2 = (targets['DESI_TARGET'] & desi_mask.LRG_2PASS) != 0
+        nobs[lrg1] = 1
         nobs[lrg2] = 2
+    except AttributeError:
+        log.error('per-pass LRG bits not set in {}'.format(desi_mask))
+    #ADM also reserve a setting for LRG_3PASS, but fail gracefully for now
+    try:
+        lrg3 = (targets['DESI_TARGET'] & desi_mask.LRG_3PASS) != 0
         nobs[lrg3] = 3
-    else:
-        nobs[islrg] = 2
+    except AttributeError:
+        pass
 
     #- TBD: flag QSOs for 4 obs ahead of time, or only after confirming
     #- that they are redshift>2.15 (i.e. good for Lyman-alpha)?

py/desitarget/test/test_numobs.py

@@ -13,12 +13,8 @@ def setUp(self):
             ('BGS_TARGET',np.int64),
             ('MWS_TARGET',np.int64),
             ('NUMOBS',np.int32),
-            ('DECAM_FLUX', '>f4', (6,)),
-            ('DECAM_MW_TRANSMISSION', '>f4', (6,)),
         ]
         self.targets = np.zeros(5, dtype=dtype)
-        self.targets['DECAM_MW_TRANSMISSION'] = 1.0
-        self.targets['DECAM_FLUX'][:,4] = 10**((22.5-np.linspace(20, 21, 5))/2.5)
 
     def test_numobs(self):
         t = self.targets
@@ -27,38 +23,30 @@ def test_numobs(self):
         with self.assertRaises(ValueError):
             calc_numobs(t)
 
-        #- ELGs and QSOs get one observation
+        #- ELGs and QSOs get one/four observations
         t['DESI_TARGET'] = desi_mask.ELG
         self.assertTrue(np.all(calc_numobs(t) == 1))
         t['DESI_TARGET'] = desi_mask.QSO
         self.assertTrue(np.all(calc_numobs(t) == 4))
 
-        #- LRG numobs depends upon zflux  (DECAM_FLUX index 4)
-        t['DESI_TARGET'] = desi_mask.LRG
+        #ADM LRG NUMOBS is defined using per-pass target bits
+        #ADM the desi_mask.LRG reference tests the default, which
+        #ADM should correspond to 2 observations
+        t['DESI_TARGET'] =  [desi_mask.LRG,
+                             desi_mask.LRG_1PASS, desi_mask.LRG_2PASS,
+                             desi_mask.LRG_1PASS, desi_mask.LRG_2PASS]
         nobs = calc_numobs(t)
-        self.assertTrue(np.all(nobs == [1, 1, 2, 3, 3]))
+        self.assertTrue(np.all(nobs == [2, 1, 2, 1, 2]))
 
         #- test astropy Table
         t = Table(t)
         nobs = calc_numobs(t)
-        self.assertTrue(np.all(nobs == [1, 1, 2, 3, 3]))
-
-        #- LRG numobs also works with ZFLUX instead of DECAM*
-        t['ZFLUX'] = t['DECAM_FLUX'][:,4] / t['DECAM_MW_TRANSMISSION'][:,4]
-        t.remove_column('DECAM_FLUX')
-        t.remove_column('DECAM_MW_TRANSMISSION')
-        nobs = calc_numobs(t)
-        self.assertTrue(np.all(nobs == [1, 1, 2, 3, 3]))
+        self.assertTrue(np.all(nobs == [2, 1, 2, 1, 2]))
 
         #- this is true even if other targeting bits are set
         t['DESI_TARGET'] |= desi_mask.mask('ELG|BGS_ANY')
         nobs = calc_numobs(t)
-        self.assertTrue(np.all(nobs == [1, 1, 2, 3, 3]))
-
-        #- But if no *FLUX available, default to LRGs with 2 obs
-        t.remove_column('ZFLUX')
-        nobs = calc_numobs(t)
-        self.assertTrue(np.all(nobs == 2))
-
+        self.assertTrue(np.all(nobs == [2, 1, 2, 1, 2]))
+
 if __name__ == '__main__':
     unittest.main()