def testHsmSourceMomentsRound(self):
for (i, imageid) in enumerate(file_indices):
source = self.runMeasurement("ext_shapeHSM_HsmSourceMomentsRound",
imageid, x_centroid[i], y_centroid[i],
sky_var[i])
x = source.get("ext_shapeHSM_HsmSourceMomentsRound_x")
y = source.get("ext_shapeHSM_HsmSourceMomentsRound_y")
xx = source.get("ext_shapeHSM_HsmSourceMomentsRound_xx")
yy = source.get("ext_shapeHSM_HsmSourceMomentsRound_yy")
xy = source.get("ext_shapeHSM_HsmSourceMomentsRound_xy")
flux = source.get("ext_shapeHSM_HsmSourceMomentsRound_Flux")
# Centroids from GalSim use the FITS lower-left corner of 1,1
offset = self.xy0 + self.offset
self.assertAlmostEqual(x - offset.getX(),
round_moments_expected[i][4] - 1, 3)
self.assertAlmostEqual(y - offset.getY(),
round_moments_expected[i][5] - 1, 3)
expected = afwEll.Quadrupole(
afwEll.SeparableDistortionDeterminantRadius(
round_moments_expected[i][1], round_moments_expected[i][2],
round_moments_expected[i][0]))
self.assertAlmostEqual(xx, expected.getIxx(), SHAPE_DECIMALS)
self.assertAlmostEqual(xy, expected.getIxy(), SHAPE_DECIMALS)
self.assertAlmostEqual(yy, expected.getIyy(), SHAPE_DECIMALS)
self.assertAlmostEqual(flux, round_moments_expected[i][3],
SHAPE_DECIMALS)
def main(rootDir, visit, ccd, n=5):
# make a butler and specify your dataId
butler = dafPersist.Butler(rootDir)
dataId = {'visit': visit, 'ccd':ccd}
# the x,y of a galaxy, as if we're computing galaxy-galaxy shear about the object at this coordinate.
gx, gy = 1000.0, 1000.0
# get the exposure from the butler
sources = butler.get('src', dataId)
for s in sources[:n]:
# get the shape and coords, and get the angle wrt x-axis
moment = s.getShape()
x, y = s.getX(), s.getY()
dx, dy = x - gx, y - gy
angle = -math.atan2(dy, dx)*afwGeom.radians
# make a rotation transform and apply it to the shape (moment)
rotation = afwGeom.LinearTransform.makeRotation(angle)
moment_rotated = moment.transform(rotation)
# convert that to a 'Separable' of a specified type of ellipticity and radius
# --> Ellipticities: Distortion, ReducedShear, ConformalShear
# --> Radii: DeterminantRadius, TraceRadius, LogDeterminantRadius, LogTraceRadius
# Constructors have the form 'Separable<ellipticity><radius>()' ... e.g.
separable_dd = ellipses.SeparableDistortionDeterminantRadius(moment_rotated)
# extract the ellipticity from the 'Separable' object
e_dis = separable_dd.getEllipticity()
# convert to other ellipticity types if you wish
e_red = ellipses.ReducedShear(e_dis)
e_con = ellipses.ConformalShear(e_dis)
# output all the different types
# Here +/- E1 are tangential and radial, respectively
for e in (e_dis, e_red, e_con):
print "%6.3f %6.3f " % (e.getE1(), e.getE2()),
print ""