fixup! RingsSkyMap: fix bugs in tract numbering

lsst · Jun 26, 2018 · 08c8846 · 08c8846
1 parent ec6d491
commit 08c8846
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Showing 2 changed files with 19 additions and 14 deletions.
diff --git a/python/lsst/skymap/ringsSkyMap.py b/python/lsst/skymap/ringsSkyMap.py
@@ -180,8 +180,9 @@ def _raToTractNum(self, ra, ringNum):
         if ringNum in (-1, self.config.numRings):
             return 0
         assert ringNum in range(self.config.numRings)
-        return int((ra - self._raStart).wrap().asRadians() /
-                   (2*math.pi/self._ringNums[ringNum]) + 0.5)
+        tractNum = int((ra - self._raStart).wrap().asRadians() /
+                       (2*math.pi/self._ringNums[ringNum]) + 0.5)
+        return 0 if tractNum == self._ringNums[ringNum] else tractNum  # Allow wraparound
 
     def findTract(self, coord):
         """Find the tract whose center is nearest the specified coord.

diff --git a/tests/test_ringsSkyMap.py b/tests/test_ringsSkyMap.py
@@ -106,6 +106,22 @@ def testDm14809(self):
         tract = self.skymap.findTract(coord)
         self.assertTrue(tract.contains(coord))
 
+    def testWraparound(self):
+        """Check wrapping at RA=0
+
+        How-to-reproduce of a bug identified by Sogo Mineo.
+        """
+        tractId = 9712
+        deviation = 10 / 3600.0  # 10 arcsec
+        tract = self.skymap[tractId]
+        center = tract.getCtrCoord()
+        centerRa = center.getRa().asDegrees()
+        centerDec = center.getDec().asDegrees()
+        for devRa in [-deviation, deviation]:
+            coord = lsst.afw.geom.SpherePoint(centerRa + devRa, centerDec, lsst.afw.geom.degrees)
+            foundTractId = self.skymap.findTract(coord).getId()
+            self.assertEqual(tractId, foundTractId)
+
     def getFirstTractLastRingCoord(self):
         """Return the coordinates of the first tract in the last ring
 
@@ -168,18 +184,6 @@ def testDm14809(self):
         tract = self.skymap.findTract(coord)
         self.assertFalse(tract.contains(coord))
 
-        # Check Mineo-san's bug report
-        tractId = 9712
-        deviation = 10 / 3600.0  # 10 arcsec
-        tract = self.skymap[tractId]
-        center = tract.getCtrCoord()
-        centerRa = center.getRa().asDegrees()
-        centerDec = center.getDec().asDegrees()
-        for devRa in [-deviation, deviation]:
-            coord = lsst.afw.geom.SpherePoint(centerRa + devRa, centerDec, lsst.afw.geom.degrees)
-            foundTractId = self.skymap.findTract(coord).getId()
-            self.assertEqual(tractId, foundTractId)
-
 
 class MemoryTester(lsst.utils.tests.MemoryTestCase):
     pass