def testWarnings(self):
"""Test that approximateWcs raises a UserWarning when it cannot achieve desired tolerance"""
radialTransform = afwGeom.makeRadialTransform([0, 2.0, 3.0])
wcs = afwGeom.makeModifiedWcs(pixelTransform=radialTransform, wcs=self.tanWcs,
modifyActualPixels=False)
with self.assertRaises(UserWarning):
approximateWcs(wcs=wcs, bbox=self.bbox, order=2)
def doTest(self, name, transform, order=3, doPlot=False):
"""Add the specified distorting transform to a TAN WCS and fit it
The resulting WCS pixelToSky method acts as follows:
pixelToSky(transform.applyForward(pixels))
"""
wcs = afwGeom.makeModifiedWcs(pixelTransform=transform,
wcs=self.tanWcs,
modifyActualPixels=False)
fitWcs = approximateWcs(
wcs=wcs,
bbox=self.bbox,
order=order,
)
if doPlot:
self.plotWcs(wcs, fitWcs, self.bbox, transform)
msg = "ERROR: %s failed with order %s" % (name, order)
self.assertWcsAlmostEqualOverBBox(wcs,
fitWcs,
self.bbox,
maxDiffSky=0.001 *
afwGeom.arcseconds,
maxDiffPix=0.02,
msg=msg)
def testWarnings(self):
"""Test that approximateWcs raises a UserWarning when it cannot achieve desired tolerance"""
radialTransform = afwGeom.makeRadialTransform([0, 2.0, 3.0])
wcs = afwGeom.makeModifiedWcs(pixelTransform=radialTransform,
wcs=self.tanWcs,
modifyActualPixels=False)
with self.assertRaises(UserWarning):
approximateWcs(wcs=wcs, bbox=self.bbox, order=2)
def doTest(self, pixelsToTanPixels, order=3):
"""Test using pixelsToTanPixels to distort the source positions
"""
distortedWcs = afwGeom.makeModifiedWcs(pixelTransform=pixelsToTanPixels, wcs=self.tanWcs,
modifyActualPixels=False)
self.exposure.setWcs(distortedWcs)
sourceCat = self.makeSourceCat(distortedWcs)
config = AstrometryTask.ConfigClass()
config.wcsFitter.order = order
config.wcsFitter.numRejIter = 0
solver = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
results = solver.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
fitWcs = self.exposure.getWcs()
self.assertRaises(Exception, self.assertWcsAlmostEqualOverBBox, fitWcs, distortedWcs)
self.assertWcsAlmostEqualOverBBox(distortedWcs, fitWcs, self.bbox,
maxDiffSky=0.01*afwGeom.arcseconds, maxDiffPix=0.02)
srcCoordKey = afwTable.CoordKey(sourceCat.schema["coord"])
refCoordKey = afwTable.CoordKey(results.refCat.schema["coord"])
refCentroidKey = afwTable.Point2DKey(results.refCat.schema["centroid"])
maxAngSep = afwGeom.Angle(0)
maxPixSep = 0
for refObj, src, d in results.matches:
refCoord = refObj.get(refCoordKey)
refPixPos = refObj.get(refCentroidKey)
srcCoord = src.get(srcCoordKey)
srcPixPos = src.getCentroid()
angSep = refCoord.separation(srcCoord)
maxAngSep = max(maxAngSep, angSep)
pixSep = math.hypot(*(srcPixPos-refPixPos))
maxPixSep = max(maxPixSep, pixSep)
print("max angular separation = %0.4f arcsec" % (maxAngSep.asArcseconds(),))
print("max pixel separation = %0.3f" % (maxPixSep,))
self.assertLess(maxAngSep.asArcseconds(), 0.0026)
self.assertLess(maxPixSep, 0.015)
# try again, but without fitting the WCS
config.forceKnownWcs = True
solverNoFit = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
self.exposure.setWcs(distortedWcs)
resultsNoFit = solverNoFit.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
self.assertIsNone(resultsNoFit.scatterOnSky)
# fitting should result in matches that are at least as good
# (strictly speaking fitting might result in a larger match list with
# some outliers, but in practice this test passes)
meanFitDist = np.mean([match.distance for match in results.matches])
meanNoFitDist = np.mean([match.distance for match in resultsNoFit.matches])
self.assertLessEqual(meanFitDist, meanNoFitDist)
def doTest(self, pixelsToTanPixels):
"""Test using pixelsToTanPixels to distort the source positions
"""
distortedWcs = afwGeom.makeModifiedWcs(pixelTransform=pixelsToTanPixels, wcs=self.tanWcs,
modifyActualPixels=False)
self.exposure.setWcs(distortedWcs)
sourceCat = self.makeSourceCat(distortedWcs)
print("number of stars =", len(sourceCat))
config = ANetAstrometryTask.ConfigClass()
solver = ANetAstrometryTask(config=config, refObjLoader=self.refObjLoader,
schema=self.makeSourceSchema())
results = solver.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
fitWcs = self.exposure.getWcs()
self.assertRaises(Exception, self.assertWcsAlmostEqualOverBBox, fitWcs, distortedWcs)
self.assertWcsAlmostEqualOverBBox(distortedWcs, fitWcs, self.bbox,
maxDiffSky=0.01*lsst.geom.arcseconds, maxDiffPix=0.02)
srcCoordKey = afwTable.CoordKey(sourceCat.schema["coord"])
refCoordKey = afwTable.CoordKey(results.refCat.schema["coord"])
maxAngSep = 0*lsst.geom.radians
maxPixSep = 0
for refObj, src, d in results.matches:
refCoord = refObj.get(refCoordKey)
refPixPos = fitWcs.skyToPixel(refCoord)
srcCoord = src.get(srcCoordKey)
srcPixPos = src.getCentroid()
angSep = refCoord.separation(srcCoord)
maxAngSep = max(maxAngSep, angSep)
pixSep = math.hypot(*(srcPixPos-refPixPos))
maxPixSep = max(maxPixSep, pixSep)
print("max angular separation = %0.4f arcsec" % (maxAngSep.asArcseconds(),))
print("max pixel separation = %0.3f" % (maxPixSep,))
self.assertLess(maxAngSep.asArcseconds(), 0.005)
self.assertLess(maxPixSep, 0.03)
# try again, but without fitting the WCS
config.forceKnownWcs = True
solverNoFit = ANetAstrometryTask(config=config, refObjLoader=self.refObjLoader,
schema=self.makeSourceSchema())
self.exposure.setWcs(distortedWcs)
noFitResults = solverNoFit.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
self.assertGreater(len(noFitResults.refCat), 300)
def testLargeDistortion(self):
# This transform is about as extreme as I can get:
# using 0.0005 in the last value appears to produce numerical issues.
# It produces a maximum deviation of 459 pixels, which should be sufficient.
pixelsToTanPixels = afwGeom.makeRadialTransform([0.0, 1.1, 0.0004])
self.distortedWcs = afwGeom.makeModifiedWcs(pixelTransform=pixelsToTanPixels,
wcs=self.wcs,
modifyActualPixels=False)
def applyDistortion(src):
out = src.table.copyRecord(src)
out.set(out.table.getCentroidKey(),
pixelsToTanPixels.applyInverse(src.getCentroid()))
return out
self.singleTestInstance(self.filename, applyDistortion)
def testLargeDistortion(self):
# This transform is about as extreme as I can get:
# using 0.0005 in the last value appears to produce numerical issues.
# It produces a maximum deviation of 459 pixels, which should be sufficient.
pixelsToTanPixels = afwGeom.makeRadialTransform([0.0, 1.1, 0.0004])
self.distortedWcs = afwGeom.makeModifiedWcs(pixelTransform=pixelsToTanPixels,
wcs=self.wcs,
modifyActualPixels=False)
def applyDistortion(src):
out = src.table.copyRecord(src)
out.set(out.table.getCentroidKey(),
pixelsToTanPixels.applyInverse(src.getCentroid()))
return out
self.singleTestInstance(self.filename, applyDistortion)
def rotateExposure(exp, nDegrees, kernelName='lanczos4', logger=None):
"""Rotate an exposure by nDegrees clockwise.
Parameters
----------
exp : `lsst.afw.image.exposure.Exposure`
The exposure to rotate
nDegrees : `float`
Number of degrees clockwise to rotate by
kernelName : `str`
Name of the warping kernel, used to instantiate the warper.
logger : `lsst.log.Log`
Logger for logging warnings
Returns
-------
rotatedExp : `lsst.afw.image.exposure.Exposure`
A copy of the input exposure, rotated by nDegrees
"""
nDegrees = nDegrees % 360
if not logger:
logger = lsstLog.getLogger('atmospec.utils')
wcs = exp.getWcs()
if not wcs:
logger.warn(
"Can't rotate exposure without a wcs - returning exp unrotated")
return exp.clone(
) # return a clone so it's always returning a copy as this is what default does
warper = afwMath.Warper(kernelName)
if isinstance(exp, afwImage.ExposureU):
# TODO: remove once this bug is fixed - DM-20258
logger.info('Converting ExposureU to ExposureF due to bug')
logger.info('Remove this workaround after DM-20258')
exp = afwImage.ExposureF(exp, deep=True)
affineRotTransform = geom.AffineTransform.makeRotation(nDegrees *
geom.degrees)
transformP2toP2 = afwGeom.makeTransform(affineRotTransform)
rotatedWcs = afwGeom.makeModifiedWcs(transformP2toP2, wcs, False)
rotatedExp = warper.warpExposure(rotatedWcs, exp)
# rotatedExp.setXY0(geom.Point2I(0, 0)) # TODO: check no longer required
return rotatedExp
def setUp(self):
# Make fake sources
self.nSources = 10
self.bbox = geom.Box2I(geom.Point2I(0, 0),
geom.Extent2I(1024, 1153))
self.xyLoc = 100
dataset = measTests.TestDataset(self.bbox)
for srcIdx in range(self.nSources):
dataset.addSource(100000.0,
geom.Point2D(srcIdx*self.xyLoc,
srcIdx*self.xyLoc))
schema = dataset.makeMinimalSchema()
schema.addField("base_PixelFlags_flag", type="Flag")
schema.addField("base_PixelFlags_flag_offimage", type="Flag")
self.exposure, catalog = dataset.realize(
10.0, schema, randomSeed=1234)
for src in catalog:
src.setCoord(self.exposure.getWcs().pixelToSky(src.getCentroid()))
# Non-invertible WCS to test robustness to distortions.
# Coefficients transform (x - 1e-7*x^3 -> x, y -> y); see docs for PolyMap.
pixelCoeffs = np.array([[-1.0e-7, 1, 3, 0],
[1.0, 1, 1, 0],
[1.0, 2, 0, 1],
])
self.exposure.setWcs(afwGeom.makeModifiedWcs(
afwGeom.TransformPoint2ToPoint2(ast.PolyMap(pixelCoeffs, 2, options="IterInverse=1")),
self.exposure.wcs,
modifyActualPixels=False
))
# Convert to task required format
self.testDiaSources = catalog.asAstropy().to_pandas()
self.testDiaSources.rename(columns={"coord_ra": "ra",
"coord_dec": "decl"},
inplace=True,)
self.testDiaSources.loc[:, "ra"] = np.rad2deg(self.testDiaSources["ra"])
self.testDiaSources.loc[:, "decl"] = np.rad2deg(self.testDiaSources["decl"])
self.testDiaSources["ssObjectId"] = 0
# Grab a subset to treat as solar system objects
self.testSsObjects = self.testDiaSources[2:8].reset_index()
# Assign them ids starting from 1.
self.testSsObjects.loc[:, "ssObjectId"] = np.arange(
1, len(self.testSsObjects) + 1, dtype=int,)
self.testSsObjects["Err(arcsec)"] = np.ones(len(self.testSsObjects))
def testMakeModifiedWcsNoActualPixels(self):
"""Test makeModifiedWcs on a SkyWcs that has no ACTUAL_PIXELS frame
"""
cdMatrix = makeCdMatrix(scale=self.scale)
originalWcs = makeSkyWcs(crpix=self.crpix,
crval=self.crvalList[0],
cdMatrix=cdMatrix)
originalFrameDict = originalWcs.getFrameDict()
# make an arbitrary but reasonable transform to insert using makeModifiedWcs
pixelTransform = makeRadialTransform([0.0, 1.0, 0.0, 0.0011])
# the result of the insertion should be as follows
desiredPixelsToSky = pixelTransform.then(originalWcs.getTransform())
pixPointList = ( # arbitrary but reasonable
Point2D(0.0, 0.0),
Point2D(1000.0, 0.0),
Point2D(0.0, 2000.0),
Point2D(-1111.0, -2222.0),
)
for modifyActualPixels in (False, True):
modifiedWcs = makeModifiedWcs(
pixelTransform=pixelTransform,
wcs=originalWcs,
modifyActualPixels=modifyActualPixels)
modifiedFrameDict = modifiedWcs.getFrameDict()
skyList = modifiedWcs.pixelToSky(pixPointList)
# compare pixels to sky
desiredSkyList = desiredPixelsToSky.applyForward(pixPointList)
self.assertSpherePointListsAlmostEqual(skyList, desiredSkyList)
# compare pixels to IWC
pixelsToIwc = TransformPoint2ToPoint2(
modifiedFrameDict.getMapping("PIXELS", "IWC"))
desiredPixelsToIwc = TransformPoint2ToPoint2(
pixelTransform.getMapping().then(
originalFrameDict.getMapping("PIXELS", "IWC")))
self.assertPairListsAlmostEqual(
pixelsToIwc.applyForward(pixPointList),
desiredPixelsToIwc.applyForward(pixPointList))
self.checkNonFitsWcs(modifiedWcs)
def doTest(self, name, transform, order=3, doPlot=False):
"""Add the specified distorting transform to a TAN WCS and fit it
The resulting WCS pixelToSky method acts as follows:
pixelToSky(transform.applyForward(pixels))
"""
wcs = afwGeom.makeModifiedWcs(pixelTransform=transform,
wcs=self.tanWcs,
modifyActualPixels=False)
fitWcs = approximateWcs(
wcs=wcs,
bbox=self.bbox,
order=order,
)
if doPlot:
self.plotWcs(wcs, fitWcs, self.bbox, transform)
msg = "ERROR: %s failed with order %s" % (name, order)
self.assertWcsAlmostEqualOverBBox(wcs, fitWcs, self.bbox,
maxDiffSky=0.001*lsst.geom.arcseconds, maxDiffPix=0.02, msg=msg)
def testMakeModifiedWcsWithActualPixels(self):
"""Test makeModifiedWcs on a SkyWcs that has an ACTUAL_PIXELS frame
"""
cdMatrix = makeCdMatrix(scale=self.scale)
baseWcs = makeSkyWcs(crpix=self.crpix,
crval=self.crvalList[0],
cdMatrix=cdMatrix)
# model actual pixels to pixels as an arbitrary zoom factor;
# this is not realistic, but is fine for a unit test
actualPixelsToPixels = TransformPoint2ToPoint2(ast.ZoomMap(2, 0.72))
originalWcs = addActualPixelsFrame(baseWcs, actualPixelsToPixels)
originalFrameDict = originalWcs.getFrameDict()
# make an arbitrary but reasonable transform to insert using makeModifiedWcs
pixelTransform = makeRadialTransform([0.0, 1.0, 0.0, 0.0011
]) # arbitrary but reasonable
pixPointList = ( # arbitrary but reasonable
Point2D(0.0, 0.0),
Point2D(1000.0, 0.0),
Point2D(0.0, 2000.0),
Point2D(-1111.0, -2222.0),
)
for modifyActualPixels in (True, False):
modifiedWcs = makeModifiedWcs(
pixelTransform=pixelTransform,
wcs=originalWcs,
modifyActualPixels=modifyActualPixels)
modifiedFrameDict = modifiedWcs.getFrameDict()
self.assertEqual(
modifiedFrameDict.getFrame(modifiedFrameDict.BASE).domain,
"ACTUAL_PIXELS")
modifiedActualPixelsToPixels = \
TransformPoint2ToPoint2(modifiedFrameDict.getMapping("ACTUAL_PIXELS", "PIXELS"))
modifiedPixelsToIwc = TransformPoint2ToPoint2(
modifiedFrameDict.getMapping("PIXELS", "IWC"))
# compare pixels to sky
skyList = modifiedWcs.pixelToSky(pixPointList)
if modifyActualPixels:
desiredPixelsToSky = pixelTransform.then(
originalWcs.getTransform())
else:
originalPixelsToSky = \
TransformPoint2ToSpherePoint(originalFrameDict.getMapping("PIXELS", "SKY"))
desiredPixelsToSky = actualPixelsToPixels.then(
pixelTransform).then(originalPixelsToSky)
desiredSkyList = desiredPixelsToSky.applyForward(pixPointList)
self.assertSpherePointListsAlmostEqual(skyList, desiredSkyList)
# compare ACTUAL_PIXELS to PIXELS and PIXELS to IWC
if modifyActualPixels:
# check that ACTUAL_PIXELS to PIXELS has been modified as expected
desiredActualPixelsToPixels = pixelTransform.then(
actualPixelsToPixels)
self.assertPairListsAlmostEqual(
modifiedActualPixelsToPixels.applyForward(pixPointList),
desiredActualPixelsToPixels.applyForward(pixPointList))
# check that PIXELS to IWC is unchanged
originalPixelsToIwc = TransformPoint2ToPoint2(
originalFrameDict.getMapping("PIXELS", "IWC"))
self.assertPairListsAlmostEqual(
modifiedPixelsToIwc.applyForward(pixPointList),
originalPixelsToIwc.applyForward(pixPointList))
else:
# check that ACTUAL_PIXELS to PIXELS is unchanged
self.assertPairListsAlmostEqual(
actualPixelsToPixels.applyForward(pixPointList),
actualPixelsToPixels.applyForward(pixPointList))
# check that PIXELS to IWC has been modified as expected
desiredPixelsToIwc = TransformPoint2ToPoint2(
pixelTransform.getMapping().then(
originalFrameDict.getMapping("PIXELS", "IWC")))
self.assertPairListsAlmostEqual(
modifiedPixelsToIwc.applyForward(pixPointList),
desiredPixelsToIwc.applyForward(pixPointList))
self.checkNonFitsWcs(modifiedWcs)
def doTest(self, pixelsToTanPixels, order=3):
"""Test using pixelsToTanPixels to distort the source positions
"""
distortedWcs = afwGeom.makeModifiedWcs(pixelTransform=pixelsToTanPixels, wcs=self.tanWcs,
modifyActualPixels=False)
self.exposure.setWcs(distortedWcs)
sourceCat = self.makeSourceCat(distortedWcs)
config = AstrometryTask.ConfigClass()
config.wcsFitter.order = order
config.wcsFitter.numRejIter = 0
solver = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
results = solver.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
fitWcs = self.exposure.getWcs()
self.assertRaises(Exception, self.assertWcsAlmostEqualOverBBox, fitWcs, distortedWcs)
self.assertWcsAlmostEqualOverBBox(distortedWcs, fitWcs, self.bbox,
maxDiffSky=0.01*lsst.geom.arcseconds, maxDiffPix=0.02)
srcCoordKey = afwTable.CoordKey(sourceCat.schema["coord"])
refCoordKey = afwTable.CoordKey(results.refCat.schema["coord"])
refCentroidKey = afwTable.Point2DKey(results.refCat.schema["centroid"])
maxAngSep = 0*lsst.geom.radians
maxPixSep = 0
for refObj, src, d in results.matches:
refCoord = refObj.get(refCoordKey)
refPixPos = refObj.get(refCentroidKey)
srcCoord = src.get(srcCoordKey)
srcPixPos = src.getCentroid()
angSep = refCoord.separation(srcCoord)
maxAngSep = max(maxAngSep, angSep)
pixSep = math.hypot(*(srcPixPos-refPixPos))
maxPixSep = max(maxPixSep, pixSep)
print("max angular separation = %0.4f arcsec" % (maxAngSep.asArcseconds(),))
print("max pixel separation = %0.3f" % (maxPixSep,))
self.assertLess(maxAngSep.asArcseconds(), 0.0038)
self.assertLess(maxPixSep, 0.021)
# try again, invoking the reference selector
config.referenceSelector.doUnresolved = True
config.referenceSelector.unresolved.name = 'resolved'
solverRefSelect = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
self.exposure.setWcs(distortedWcs)
resultsRefSelect = solverRefSelect.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
self.assertLess(len(resultsRefSelect.matches), len(results.matches))
# try again, but without fitting the WCS, no reference selector
config.referenceSelector.doUnresolved = False
config.forceKnownWcs = True
solverNoFit = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
self.exposure.setWcs(distortedWcs)
resultsNoFit = solverNoFit.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
self.assertIsNone(resultsNoFit.scatterOnSky)
# fitting should result in matches that are at least as good
# (strictly speaking fitting might result in a larger match list with
# some outliers, but in practice this test passes)
meanFitDist = np.mean([match.distance for match in results.matches])
meanNoFitDist = np.mean([match.distance for match in resultsNoFit.matches])
self.assertLessEqual(meanFitDist, meanNoFitDist)
# try once again, without fitting the WCS, with the reference selector
# (this goes through a different code path)
config.referenceSelector.doUnresolved = True
solverNoFitRefSelect = AstrometryTask(config=config, refObjLoader=self.refObjLoader)
resultsNoFitRefSelect = solverNoFitRefSelect.run(
sourceCat=sourceCat,
exposure=self.exposure,
)
self.assertLess(len(resultsNoFitRefSelect.matches), len(resultsNoFit.matches))
