DM-11594: test_distortion fails when run from pytest

.gitignore

@@ -4,6 +4,7 @@ _build.*
 *.os
 *.pyc
 *.so
+.cache
 *~
 #*
 *#

tests/test_distortion.py

@@ -25,18 +25,16 @@
 import os.path
 import unittest
 import pickle
-from collections import namedtuple
 
 import lsst.utils.tests
 from lsst.obs.hsc import HscMapper
+from lsst.pipe.base import Struct
 from lsst.afw.cameraGeom import FOCAL_PLANE, PUPIL, PIXELS
 
 # Set SAVE_DATA True to save new distortion data; this will make the test fail,
 # to remind you to set it False before committing the code.
 SAVE_DATA = False
 
-CcdData = namedtuple("CcdData", ['serial', 'cornerDict'])
-CornerData = namedtuple("CornerData", ['focalPlane', "pupil", "focalPlaneRoundTrip", "pixPosRoundTrip"])
 DataFileName = "data/distortionData.pickle"  # path relative to the tests directory
 
 
@@ -68,19 +66,32 @@ def testDistortion(self):
         for detectorName, ccdData in newData.items():
             savedCcdData = savedData[detectorName]
             self.assertEqual(ccdData.serial, savedCcdData.serial)
-            for pixPos, cornerData in ccdData.cornerDict.items():
-                savedCornerData = savedCcdData.cornerDict[pixPos]
+            for pixPosKey, cornerData in ccdData.cornerDict.items():
+                savedCornerData = savedCcdData.cornerDict[pixPosKey]
+                self.assertEqual(cornerData.pixPos, savedCornerData.pixPos)
                 self.assertPairsAlmostEqual(cornerData.focalPlane, savedCornerData.focalPlane)
-                self.assertPairsAlmostEqual(cornerData.pupil, savedCornerData.pupil)
-                self.assertPairsAlmostEqual(cornerData.focalPlaneRoundTrip,
-                                            savedCornerData.focalPlaneRoundTrip)
-                self.assertPairsAlmostEqual(cornerData.pixPosRoundTrip, savedCornerData.pixPosRoundTrip)
+                self.assertPairsAlmostEqual(cornerData.fieldAngle, savedCornerData.fieldAngle)
+                self.assertPairsAlmostEqual(cornerData.focalPlaneRoundTrip, cornerData.focalPlane,
+                                            maxDiff=0.01)
+                self.assertPairsAlmostEqual(cornerData.pixPosRoundTrip, cornerData.pixPos, maxDiff=0.01)
 
     def makeDistortionData(self):
         """Make distortion data
+
+        The data format is a dict of detector name: ccdData, where
+        ccdData is a Struct containing these fields:
+        - serial: detector.getSerial
+        - cornerDict: a dict of pixPosKey, cornerData, where:
+            - pixPosKey: self.asKey(pixPos) where pixPos is pixel position
+            - cornerData is Struct contains these fields (all of type lsst.afw.geom.Point2D):
+                - pixPos: pixel position
+                - focalPlane: focal plane position computed from pixPos
+                - fieldAngle: fieldAngle position computed from focalPlane
+                - focalPlaneRoundTrip: focal plane position computed from fieldAngle
+                - pixPosRoundTrip: pixel position computed from focalPlane
         """
         camera = HscMapper(root=".").camera
-        focalPlaneToPupil = camera.getTransformMap().get(PUPIL)
+        focalPlaneToFieldAngle = camera.getTransformMap().get(PUPIL)
         data = {}  # dict of detector name: CcdData
         for detector in camera:
             # for each corner of each CCD:
@@ -93,22 +104,26 @@ def makeDistortionData(self):
             pixelsToFocalPlane = detector.getTransform(FOCAL_PLANE)
             cornerDict = {}
             for pixPos in detector.getCorners(PIXELS):
+                pixPos = pixPos
                 focalPlane = pixelsToFocalPlane.forwardTransform(pixPos)
-                pupil = focalPlaneToPupil.forwardTransform(focalPlane)
-                focalPlaneRoundTrip = focalPlaneToPupil.reverseTransform(pupil)
-                pixPosRoundTrip = pixelsToFocalPlane.reverseTransform(focalPlaneRoundTrip)
-                # Use a tuple (x, y) as a the key instead of a Point2D, for assured reasonable hashability
-                cornerDict[(pixPos[0], pixPos[1])] = CornerData(
+                fieldAngle = focalPlaneToFieldAngle.forwardTransform(focalPlane)
+                focalPlaneRoundTrip = focalPlaneToFieldAngle.reverseTransform(fieldAngle)
+                pixPosRoundTrip = pixelsToFocalPlane.reverseTransform(focalPlane)
+                cornerDict[self.toKey(pixPos)] = Struct(
+                    pixPos = pixPos,
                     focalPlane = focalPlane,
-                    pupil = pupil,
+                    fieldAngle = fieldAngle,
                     focalPlaneRoundTrip = focalPlaneRoundTrip,
                     pixPosRoundTrip = pixPosRoundTrip,
                 )
 
-            data[detector.getName()] = CcdData(serial=detector.getSerial(), cornerDict=cornerDict)
+            data[detector.getName()] = Struct(serial=detector.getSerial(), cornerDict=cornerDict)
 
         return data
 
+    def toKey(self, pixPos):
+        return "(%0.1f, %0.1f)" % tuple(pixPos)
+
 
 class TestMemory(lsst.utils.tests.MemoryTestCase):
     def setUp(self):