def testZogyNewImplementation(self):
"""DM-25115 implementation test.
Notes
-----
See diffimTests: tickets/DM-25115_zogy_implementation/DM-25115_zogy_unit_test_development.ipynb
"""
# self.svar = svar # variance of noise in science image
# self.tvar = tvar # variance of noise in template image
# Sourceless case
self.im1ex, self.im2ex \
= makeFakeImages(size=(256, 256), svar=100., tvar=100.,
psf1=self.psf1_sigma, psf2=self.psf2_sigma,
n_sources=0, psf_yvary_factor=0, varSourceChange=0.1,
seed=1, verbose=False)
config = ZogyConfig()
config.scaleByCalibration = False
task = ZogyTask(config=config)
res = task.run(self.im1ex, self.im2ex)
bbox = res.diffExp.getBBox()
subBbox = bbox.erodedBy(lsst.geom.Extent2I(25, 25))
subExp = res.diffExp[subBbox]
pixvar = self._computePixelVariance(subExp.maskedImage)
varmean = self._computeVarianceMean(subExp.maskedImage)
# Due to 3 sigma clipping, this is not so precise
self.assertFloatsAlmostEqual(pixvar, 200, rtol=0.1, atol=None)
self.assertFloatsAlmostEqual(varmean, 200, rtol=0.05, atol=None)
S = res.scoreExp.image.array / np.sqrt(res.scoreExp.variance.array)
self.assertLess(np.amax(S), 5.) # Source not detected
# ==========
self.im1ex, self.im2ex \
= makeFakeImages(size=(256, 256), svar=10., tvar=10.,
psf1=self.psf1_sigma, psf2=self.psf2_sigma,
n_sources=10, psf_yvary_factor=0, varSourceChange=0.1,
seed=1, verbose=False)
task = ZogyTask(config=config)
res = task.run(self.im1ex, self.im2ex)
S = res.scoreExp.image.array / np.sqrt(res.scoreExp.variance.array)
self.assertGreater(np.amax(S), 5.) # Source detected
def testPixelOffset(self):
""" Test whether the peak position is at [300][300].
"""
self._setUpImages()
config = ZogyConfig(scaleByCalibration=False)
task = ZogyTask(config=config)
D_F = task.run(self.imnex, self.imrex, calculateScore=False)
max_loc = PixelOffsetTest._find_max(D_F.diffExp.image.array)
self.assertEqual(max_loc, (300, 300))
def wrapZogyDiffim(config, templateExposure, scienceExposure):
"""Prepare and run ZOGY-style image differencing.
Parameters
----------
config : `lsst.pex.config.Config`
The image differencing Task configuration settings.
templateExposure : `lsst.afw.image.ExposureF`
The reference image to subtract from the science image.
scienceExposure : `lsst.afw.image.ExposureF`
The science image.
Returns
-------
`lsst.afw.image.ExposureF`
The image difference.
"""
config.scaleByCalibration = False
zogyTask = ZogyTask(config=config)
result = zogyTask.run(scienceExposure, templateExposure)
return result.diffExp