Class lsst::shapelet::RadialProfile

class RadialProfile

Registry and utility class for multi-Gaussian approximations to radial profiles.

RadialProfile provides C++ access to the saved multi-Gaussian approximations stored in the pickle files in the data subdirectory of the shapelet package, by maintaining a singleton registry of these that is populated at import time by tractor.py. It also provides access to the true (exact) profiles, (mostly useful for educational/diagnostic purposes) and information about the relationship between different radii for this profile (see getMomentsRadiusFactor()).

Each RadialProfile object represents a particular “true” profile, and can hold multiple multi-Gaussian (or multi-Shapelet) approximations with different degrees of fidelity, as controlled by the number of components in the approximation and the maximum radius at which the approximation was fit. For more information about these approximations, see tractor.py and references therein. All RadialProfiles are defined in units of the half-light radius of the true profile, even for profiles for which this is not the radius typically used.

Several predefined subclasses of RadialProfile are defined privately, and can be accessed by name through the static get() method:

• ”gaussian”: a single Gaussian profile

• ”exp”: Exponential profile (Sersic n=1)

• ”ser2”: Sersic profile with n=2

• ”ser3”: Sersic profile with n=3

• ”dev”: de Vaucouleur profile (Sersic n=4)

• ”ser5”: Sersic profile with n=5

• ”lux”: SDSS truncated Exponential profile

• ”luv”: SDSS truncated and softened de Vaucouleur profile