Add unit test for default zero-points

tests/testDefaultZeroPoint.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+
+# 
+# LSST Data Management System
+#
+# Copyright 2008-2016  AURA/LSST.
+# 
+# This product includes software developed by the
+# LSST Project (http://www.lsst.org/).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the LSST License Statement and 
+# the GNU General Public License along with this program.  If not, 
+# see <https://www.lsstcorp.org/LegalNotices/>.
+#
+
+import unittest
+import numpy as np
+
+import lsst.afw.image as afwImage
+import lsst.afw.coord as afwCoord
+import lsst.afw.geom as afwGeom
+import lsst.meas.modelfit as measModel
+import lsst.utils
+
+class DefaultZeroPointTestCase(lsst.utils.tests.TestCase):
+    '''Test that calib objects containing invalid zero-points are replaced with default calib having a
+    zero-point of magnitude 27.
+    '''
+    def setUp(self):
+        '''Create two calibs, one with a valid zero-point and one without. Use these to create two UnitSystem
+        objects.
+        '''
+        self.mag2Flux = lambda m: 10.0**(m/2.5)
+        self.flux2Mag = lambda f: 2.5*np.log10(f)
+
+        calibNoZero = afwImage.Calib()
+        calibWithZero = afwImage.Calib()
+        calibWithZero.setFluxMag0(self.mag2Flux(25))
+
+        cdelt = (0.2*afwGeom.arcseconds).asDegrees()
+        position = afwCoord.IcrsCoord(45.0*afwGeom.degrees, 45.0*afwGeom.degrees)
+        wcs = afwImage.makeWcs(position, afwGeom.Point2D(), cdelt, 0.0, 0.0, cdelt)
+
+        self.unitNoZero = measModel.UnitSystem(wcs, calibNoZero)
+        self.unitWithZero = measModel.UnitSystem(wcs, calibWithZero)
+
+    def testZeroPoint(self):
+        '''Verify that the UnitSystem with an invalid calib gets populated with a valid calib, and that
+        nothing happens to the UnitSystem with a valid calib.
+        '''
+        magNoZero = self.flux2Mag(self.unitNoZero.calib.getFluxMag0()[0])
+        magWithZero = self.flux2Mag(self.unitWithZero.calib.getFluxMag0()[0])
+
+        print(magNoZero,magWithZero)
+
+        self.assertAlmostEqual(magNoZero, 27, 6)
+        self.assertAlmostEqual(magWithZero, 25, 6)
+
+    def tearDown(self):
+        del self.unitNoZero
+        del self.unitWithZero
+
+def suite():
+    '''Returns a suite containing all the test cases in this module.'''
+
+    lsst.utils.tests.init()
+
+    suites = []
+    suites += unittest.makeSuite(DefaultZeroPointTestCase)
+    suites += unittest.makeSuite(lsst.utils.tests.MemoryTestCase)
+    return unittest.TestSuite(suites)
+
+def run(shouldExit=False):
+    """Run the tests"""
+    lsst.utils.tests.run(suite(), shouldExit)
+
+if __name__ == '__main__':
+    run(True)