def averageRaDec(ra, dec):
"""Calculate average RA, Dec from input lists using spherical geometry.
Parameters
----------
ra : `list` [`float`]
RA in [radians]
dec : `list` [`float`]
Dec in [radians]
Returns
-------
float, float
meanRa, meanDec -- Tuple of average RA, Dec [radians]
"""
assert (len(ra) == len(dec))
angleRa = [geom.Angle(r, geom.radians) for r in ra]
angleDec = [geom.Angle(d, geom.radians) for d in dec]
coords = [
geom.SpherePoint(ar, ad, geom.radians)
for (ar, ad) in zip(angleRa, angleDec)
]
meanRa, meanDec = geom.averageSpherePoint(coords)
return meanRa.asRadians(), meanDec.asRadians()
def checkCircle(center, start, numPts, maxSep=1.0e-9*geom.arcseconds):
"""Generate points in a circle; test that average is in the center
"""
coords = []
deltaAngle = 360*degrees / numPts
for ii in range(numPts):
new = start.rotated(center, ii*deltaAngle)
coords.append(new)
result = geom.averageSpherePoint(coords)
self.assertSpherePointsAlmostEqual(center, result, maxSep=maxSep)
def checkCircle(center, start, numPts, maxSep=1.0e-9*geom.arcseconds):
"""Generate points in a circle; test that average is in the center
"""
coords = []
deltaAngle = 360*degrees / numPts
for ii in range(numPts):
new = start.rotated(center, ii*deltaAngle)
coords.append(new)
result = geom.averageSpherePoint(coords)
self.assertSpherePointsAlmostEqual(center, result, maxSep=maxSep)
def updateCatalogs(self,
matchIndex,
diaSrc,
diaSources,
ccdVisit,
diaSourceId,
diaObjCat,
diaObjCoords,
healPixIndices):
"""Update DiaObject and DiaSource values after an association.
Parameters
----------
matchIndex : `int`
Array index location of the DiaObject that ``diaSrc`` was
associated to.
diaSrc : `pandas.Series`
Full unassociated DiaSource to create a DiaObject from.
diaSources : `pandas.DataFrame`
DiaSource catalog to update information in. The catalog is
modified in place.
ccdVisit : `int`
Unique identifier of the ccdVisit where ``diaSrc`` was observed.
diaSourceId : `int`
Unique identifier of the DiaSource.
diaObjectCat : `list` of `dict`s
Catalog of diaObjects to append the new object o.
diaObjectCoords : `list` of `list`s of `lsst.geom.SpherePoint`s
Set of coordinates of DiaSource locations that make up the
DiaObject average coordinate.
healPixIndices : `list` of `int`s
HealPix indices representing the locations of each currently
existing DiaObject.
"""
# Update location and healPix index.
sphPoint = geom.SpherePoint(diaSrc["ra"],
diaSrc["decl"],
geom.degrees)
diaObjCoords[matchIndex].append(sphPoint)
aveCoord = geom.averageSpherePoint(diaObjCoords[matchIndex])
diaObjCat[matchIndex]["ra"] = aveCoord.getRa().asDegrees()
diaObjCat[matchIndex]["decl"] = aveCoord.getDec().asDegrees()
nSources = diaObjCat[matchIndex]["nDiaSources"]
diaObjCat[matchIndex]["nDiaSources"] = nSources + 1
healPixIndices[matchIndex] = toIndex(self.config.nside,
diaObjCat[matchIndex]["ra"],
diaObjCat[matchIndex]["decl"])
# Update DiaObject Id that this source is now associated to.
diaSources.loc[(ccdVisit, diaSourceId), "diaObjectId"] = \
diaObjCat[matchIndex]["diaObjectId"]
def _computeMeanPos(df):
aveCoord = geom.averageSpherePoint(
list(
geom.SpherePoint(src["ra"], src["decl"], geom.degrees)
for idx, src in df.iterrows()))
ra = aveCoord.getRa().asDegrees()
decl = aveCoord.getDec().asDegrees()
if np.isnan(ra) or np.isnan(decl):
radecTai = np.nan
else:
radecTai = df["midPointTai"].max()
return pd.Series({
"ra": aveCoord.getRa().asDegrees(),
"decl": aveCoord.getDec().asDegrees(),
"radecTai": radecTai
})
def _set_mean_position(dia_object_record, dia_sources):
"""Compute and set the mean position of the input dia_object_record using
the positions of the input catalog of DIASources.
Parameters
----------
dia_object_record : `dict` or `pandas.Series`
SourceRecord of the DIAObject to edit.
dia_sources : `pandas.DataFrame`
Catalog of DIASources to compute a mean position from.
"""
coord_list = [
geom.SpherePoint(src["ra"], src["decl"], geom.degrees)
for idx, src in dia_sources.iterrows()
]
ave_coord = geom.averageSpherePoint(coord_list)
dia_object_record["ra"] = ave_coord.getRa().asDegrees()
dia_object_record["decl"] = ave_coord.getDec().asDegrees()
def calculateCircle(self, catalog):
"""Calculate a circle enclosing the catalog.
Parameters
----------
catalog : `lsst.afw.table.SourceCatalog`
Catalog to encircle.
Returns
-------
result : `lsst.pipe.base.Struct`
Result struct with components:
``center``
ICRS center coordinate (`lsst.afw.geom.SpherePoint`).
``radius``
Radius of the circle (`lsst.geom.Angle`).
"""
coordList = [src.getCoord() for src in catalog]
center = averageSpherePoint(coordList)
radius = max(center.separation(coord) for coord in coordList)
return Struct(center=center, radius=radius + self.config.matchRadius*arcseconds)