averageRaFromCat

lsst.validate.drp.util.averageRaFromCat(cat)

Compute the average right ascension from a catalog of measurements.

This function is used as an aggregate function to extract just RA from lsst.validate.drp.matchreduce.build_matched_dataset

The actual computation involves both RA and Dec.

The intent is to use this for a set of measurements of the same source but that’s neither enforced nor required.

Parameters:

cat : collection

Object with .get method for ‘coord_ra’, ‘coord_dec’ that returns radians.

Returns:

ra_mean : float

Mean RA in radians.