def test_chebyshev_evaluate(self, seed=1000):
"""
Test the evaluation of chebyshev polynomials.
Parameters
----------
seed: `int`, optional
Numpy random seed
"""
# Set numpy seed for stability
np.random.seed(seed=seed)
xPos = self.xSize * np.random.rand(self.nStar)
yPos = self.ySize * np.random.rand(self.nStar)
bbox = lsst.geom.Box2I(lsst.geom.Point2I(0, 0),
lsst.geom.Point2I(self.xSize - 1, self.ySize - 1))
# Compute the chebyshev values using the fgcm code
fgcmField = fgcm.fgcmUtilities.Cheb2dField(self.xSize, self.ySize,
self.pars)
fgcmValues = fgcmField.evaluate(xPos, yPos)
# Compute the chebyshev values using the afw code
field = afwMath.ChebyshevBoundedField(bbox, self.pars)
fieldValues = field.evaluate(xPos, yPos)
self.assertFloatsAlmostEqual(fieldValues, fgcmValues, rtol=5e-15)
def _getChebyshevPhotoCalib(self, coefficients, err, xyMax, offset,
scaling):
"""
Get the PhotoCalib object from a chebyshev polynomial zeropoint.
Parameters
----------
coefficients: `np.array`
Flattened array of chebyshev coefficients
err: `float`
Error on zeropoint
xyMax: `list` of length 2
Maximum x and y of the chebyshev bounding box
offset: `float`
Absolute calibration offset
scaling: `float`
Flat scaling value from fgcmBuildStars
Returns
-------
photoCalib: `afwImage.PhotoCalib`
"""
orderPlus1 = self.chebyshevOrder + 1
pars = np.zeros((orderPlus1, orderPlus1))
bbox = lsst.geom.Box2I(lsst.geom.Point2I(0.0, 0.0),
lsst.geom.Point2I(*xyMax))
# Take the zeropoint, apply the absolute relative calibration offset,
# and whatever flat-field scaling was applied
pars[:, :] = (coefficients.reshape(orderPlus1, orderPlus1) *
(offset * units.ABmag).to_value(units.nJy) * scaling)
field = afwMath.ChebyshevBoundedField(bbox, pars)
calibMean = field.mean()
calibErr = (np.log(10.) / 2.5) * calibMean * err
photoCalib = afwImage.PhotoCalib(field, calibErr)
return photoCalib
def _getChebyshevBoundedField(self,
coefficients,
xyMax,
offset=0.0,
scaling=1.0):
"""
Make a ChebyshevBoundedField from fgcm coefficients, with optional offset
and scaling.
Parameters
----------
coefficients: `numpy.array`
Flattened array of chebyshev coefficients
xyMax: `list` of length 2
Maximum x and y of the chebyshev bounding box
offset: `float`, optional
Absolute calibration offset. Default is 0.0
scaling: `float`, optional
Flat scaling value from fgcmBuildStars. Default is 1.0
Returns
-------
boundedField: `lsst.afw.math.ChebyshevBoundedField`
"""
orderPlus1 = int(np.sqrt(coefficients.size))
pars = np.zeros((orderPlus1, orderPlus1))
bbox = lsst.geom.Box2I(lsst.geom.Point2I(0.0, 0.0),
lsst.geom.Point2I(*xyMax))
pars[:, :] = (coefficients.reshape(orderPlus1, orderPlus1) *
(10.**(offset / -2.5)) * scaling)
boundedField = afwMath.ChebyshevBoundedField(bbox, pars)
return boundedField
def testCoaddApCorrMap(self):
"""Check that we can create and use a coadd ApCorrMap."""
coaddBox = afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(100, 100))
scale = 5.0e-5*afwGeom.degrees
cdMatrix = afwGeom.makeCdMatrix(scale=scale)
crval = afwGeom.SpherePoint(0.0, 0.0, afwGeom.degrees)
center = afwGeom.Point2D(afwGeom.Extent2D(coaddBox.getDimensions())*0.5)
coaddWcs = afwGeom.makeSkyWcs(crpix=afwGeom.Point2D(0, 0), crval=crval, cdMatrix=cdMatrix)
schema = afwTable.ExposureTable.makeMinimalSchema()
weightKey = schema.addField("customweightname", type="D", doc="Coadd weight")
catalog = afwTable.ExposureCatalog(schema)
# Non-overlapping
num = 5
inputBox = afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(10, 10))
validBox = afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(7, 7))
pointList = []
pointListValid = []
for i in range(num):
value = np.array([[1]], dtype=float) # Constant with value = i+1
apCorrMap = afwImage.ApCorrMap()
bf = afwMath.ChebyshevBoundedField(inputBox, value*(i + 1))
apCorrMap.set("only", bf)
point = afwGeom.Point2D(0, 0) - afwGeom.Extent2D(coaddBox.getDimensions())*(i+0.5)/num
wcs = afwGeom.makeSkyWcs(crpix=point, crval=crval, cdMatrix=cdMatrix)
center = afwGeom.Box2D(inputBox).getCenter()
pointList.append(coaddWcs.skyToPixel(wcs.pixelToSky(center)))
# This point will only be valid for the second overlapping record
pointValid = center + afwGeom.Extent2D(4, 4)
pointListValid.append(coaddWcs.skyToPixel(wcs.pixelToSky(pointValid)))
# A record with the valid polygon defining a limited region
record = catalog.getTable().makeRecord()
record.setWcs(wcs)
record.setBBox(inputBox)
record.setApCorrMap(apCorrMap)
record.set(weightKey, i + 1)
record['id'] = i
record.setValidPolygon(afwGeom.Polygon(afwGeom.Box2D(validBox)))
catalog.append(record)
# An overlapping record with the whole region as valid
record = catalog.getTable().makeRecord()
record.setWcs(wcs)
record.setBBox(inputBox)
apCorrMap = afwImage.ApCorrMap()
bf = afwMath.ChebyshevBoundedField(inputBox, value*(i + 2))
apCorrMap.set("only", bf)
record.setApCorrMap(apCorrMap)
record.set(weightKey, i + 2)
record['id'] = i + num
record.setValidPolygon(afwGeom.Polygon(afwGeom.Box2D(inputBox)))
catalog.append(record)
apCorrMap = measAlg.makeCoaddApCorrMap(catalog, coaddBox, coaddWcs, "customweightname")
# This will test a point where both records contribute
self.assertApCorrMap(apCorrMap, pointList)
# Only the second record will be valid for this point
self.assertApCorrMapValid(apCorrMap, pointListValid)
filename = os.path.join(os.path.dirname(os.path.realpath(__file__)), "coaddApCorrMap.fits")
exposure = afwImage.ExposureF(1, 1)
exposure.getInfo().setApCorrMap(apCorrMap)
exposure.writeFits(filename)
exposure = afwImage.ExposureF(filename)
self.assertApCorrMap(exposure.getInfo().getApCorrMap(), pointList)
self.assertApCorrMapValid(exposure.getInfo().getApCorrMap(), pointListValid)
os.unlink(filename)
def _outputZeropoints(self, butler, offsets):
"""
Output the zeropoints in jointcal_photoCalib format.
Parameters
----------
butler: lsst.daf.persistence.Butler
"""
self.log.info("Outputting jointcal_photoCalib objects")
zptCat = butler.get('fgcmZeropoints', fgcmcycle=self.useCycle)
visitCat = butler.get('fgcmVisitCatalog')
# Only output those that we have a calibration
selected = (zptCat['fgcmflag'] < 16)
# Get the mapping from filtername to dataId filter name
filterMapping = {}
nFound = 0
for rec in zptCat[selected]:
if rec['filtername'] in filterMapping:
continue
dataId = {
self.visitDataRefName: int(rec['visit']),
self.ccdDataRefName: int(rec['ccd'])
}
dataRef = butler.dataRef('raw', dataId=dataId)
filterMapping[rec['filtername']] = dataRef.dataId['filter']
nFound += 1
if nFound == len(self.filterToBand):
break
# Get a mapping from filtername to the offsets
offsetMapping = {}
for f in self.filterToBand:
offsetMapping[f] = offsets[self.bands.index(self.filterToBand[f])]
# Get a mapping from "ccd" to the ccd index used for the scaling
camera = butler.get('camera')
ccdMapping = {}
for ccdIndex, detector in enumerate(camera):
ccdMapping[detector.getId()] = ccdIndex
# And a mapping to get the flat-field scaling values
scalingMapping = {}
for rec in visitCat:
scalingMapping[rec['visit']] = rec['scaling']
# Make a fixed variable to hold the parameters to build a ChebyshevBoundedField
orderPlus1 = self.chebyshevOrder + 1
pars = np.zeros((orderPlus1, orderPlus1))
for rec in zptCat[selected]:
if self.superStarSubCcd:
# Spatially varying zeropoint
bbox = lsst.geom.Box2I(
lsst.geom.Point2I(0.0, 0.0),
lsst.geom.Point2I(*rec['fgcmfzptchebxymax']))
# Take the zeropoint, apply the absolute relative calibration offset,
# and whatever flat-field scaling was applied
pars[:, :] = (
rec['fgcmfzptcheb'].reshape(orderPlus1, orderPlus1) *
10.**(offsetMapping[rec['filtername']] / (-2.5)) *
scalingMapping[rec['visit']][ccdMapping[rec['ccd']]])
# Apply absolute relative calibration offset to 0/0 term
field = afwMath.ChebyshevBoundedField(bbox, pars)
calibMean = field.mean()
calibErr = (np.log(10.) / 2.5) * calibMean * rec['fgcmzpterr']
photoCalib = afwImage.PhotoCalib(field, calibErr)
else:
# Spatially constant zeropoint
# Take the zeropoint, apply the absolute relative calibration offset,
# and whatever flat-field scaling was applied
calibMean = (
10.**(rec['fgcmzpt'] / (-2.5)) *
10.**(offsetMapping[rec['filtername']] / (-2.5)) *
scalingMapping[rec['visit']][ccdMapping[rec['ccd']]])
calibErr = (np.log(10.) / 2.5) * calibMean * rec['fgcmzpterr']
photoCalib = afwImage.PhotoCalib(calibMean, calibErr)
butler.put(photoCalib,
'jointcal_photoCalib',
dataId={
self.visitDataRefName: int(rec['visit']),
self.ccdDataRefName: int(rec['ccd']),
'filter': filterMapping[rec['filtername']],
'tract': 0
})
self.log.info("Done outputting jointcal_photoCalib objects")
def testUndeblendedMeasurement(self):
"""Check undeblended measurement and aperture correction"""
width, height = 100, 100 # Dimensions of image
x0, y0 = 1234, 5678 # Offset of image
radius = 3.0 # Aperture radius
xCenter, yCenter = width//2, height//2 # Position of first source; integer values, for convenience
xOffset, yOffset = 1, 1 # Offset from first source to second source
flux1, flux2 = 1000, 1 # Flux of sources
apCorrValue = 3.21 # Aperture correction value to apply
image = afwImage.MaskedImageF(afwGeom.ExtentI(width, height))
image.setXY0(x0, y0)
image.getVariance().set(1.0)
schema = afwTable.SourceTable.makeMinimalSchema()
schema.addField("centroid_x", type=np.float64)
schema.addField("centroid_y", type=np.float64)
schema.addField("centroid_flag", type='Flag')
schema.getAliasMap().set("slot_Centroid", "centroid")
sfmConfig = measBase.SingleFrameMeasurementConfig()
algName = "base_CircularApertureFlux"
for subConfig in (sfmConfig.plugins, sfmConfig.undeblended):
subConfig.names = [algName]
subConfig[algName].radii = [radius]
subConfig[algName].maxSincRadius = 0 # Disable sinc photometry because we're undersampled
slots = sfmConfig.slots
slots.centroid = "centroid"
slots.shape = None
slots.psfShape = None
slots.apFlux = None
slots.modelFlux = None
slots.psfFlux = None
slots.instFlux = None
slots.calibFlux = None
fieldName = lsst.meas.base.CircularApertureFluxAlgorithm.makeFieldPrefix(algName, radius)
measBase.addApCorrName(fieldName)
apCorrConfig = measBase.ApplyApCorrConfig()
apCorrConfig.proxies = {"undeblended_" + fieldName: fieldName}
sfm = measBase.SingleFrameMeasurementTask(config=sfmConfig, schema=schema)
apCorr = measBase.ApplyApCorrTask(config=apCorrConfig, schema=schema)
cat = afwTable.SourceCatalog(schema)
parent = cat.addNew()
parent.set("centroid_x", x0 + xCenter)
parent.set("centroid_y", y0 + yCenter)
spanSetParent = afwGeom.SpanSet.fromShape(int(radius))
spanSetParent = spanSetParent.shiftedBy(x0 + xCenter, y0 + yCenter)
parent.setFootprint(afwDetection.Footprint(spanSetParent))
# First child is bright, dominating the blend
child1 = cat.addNew()
child1.set("centroid_x", parent.get("centroid_x"))
child1.set("centroid_y", parent.get("centroid_y"))
child1.setParent(parent.getId())
image.set(xCenter, yCenter, (flux1, 0, 0))
spanSetChild1 = afwGeom.SpanSet.fromShape(1)
spanSetChild1 = spanSetChild1.shiftedBy(x0 + xCenter, y0 + yCenter)
foot1 = afwDetection.Footprint(spanSetChild1)
child1.setFootprint(afwDetection.HeavyFootprintF(foot1, image))
# Second child is fainter, but we want to be able to measure it!
child2 = cat.addNew()
child2.set("centroid_x", parent.get("centroid_x") + xOffset)
child2.set("centroid_y", parent.get("centroid_y") + yOffset)
child2.setParent(parent.getId())
image.set(xCenter + xOffset, yCenter + yOffset, (flux2, 0, 0))
spanSetChild2 = afwGeom.SpanSet.fromShape(1)
tmpPoint = (x0 + xCenter + xOffset, y0 + yCenter + yOffset)
spanSetChild2 = spanSetChild2.shiftedBy(*tmpPoint)
foot2 = afwDetection.Footprint(spanSetChild2)
child2.setFootprint(afwDetection.HeavyFootprintF(foot2, image))
spans = foot1.spans.union(foot2.spans)
bbox = afwGeom.Box2I()
bbox.include(foot1.getBBox())
bbox.include(foot2.getBBox())
parent.setFootprint(afwDetection.Footprint(spans, bbox))
exposure = afwImage.makeExposure(image)
sfm.run(cat, exposure)
def checkSource(source, baseName, expectedFlux):
"""Check that we get the expected results"""
self.assertEqual(source.get(baseName + "_flux"), expectedFlux)
self.assertGreater(source.get(baseName + "_fluxSigma"), 0)
self.assertFalse(source.get(baseName + "_flag"))
# Deblended
checkSource(child1, fieldName, flux1)
checkSource(child2, fieldName, flux2)
# Undeblended
checkSource(child1, "undeblended_" + fieldName, flux1 + flux2)
checkSource(child2, "undeblended_" + fieldName, flux1 + flux2)
# Apply aperture correction
apCorrMap = afwImage.ApCorrMap()
apCorrMap[fieldName + "_flux"] = afwMath.ChebyshevBoundedField(
image.getBBox(),
apCorrValue*np.ones((1, 1), dtype=np.float64)
)
apCorrMap[fieldName + "_fluxSigma"] = afwMath.ChebyshevBoundedField(
image.getBBox(),
apCorrValue*np.zeros((1, 1), dtype=np.float64)
)
apCorr.run(cat, apCorrMap)
# Deblended
checkSource(child1, fieldName, flux1*apCorrValue)
checkSource(child2, fieldName, flux2*apCorrValue)
# Undeblended
checkSource(child1, "undeblended_" + fieldName, (flux1 + flux2)*apCorrValue)
checkSource(child2, "undeblended_" + fieldName, (flux1 + flux2)*apCorrValue)
self.assertIn(fieldName + "_apCorr", schema)
self.assertIn(fieldName + "_apCorrSigma", schema)
self.assertIn("undeblended_" + fieldName + "_apCorr", schema)
self.assertIn("undeblended_" + fieldName + "_apCorrSigma", schema)
