lsst.pipe.tasks.colorterms.Colorterm Class Reference

Colorterm correction for one pair of filters. More...

Inheritance diagram for lsst.pipe.tasks.colorterms.Colorterm:

Public Member Functions
def	transformSource
	Transform the brightness of a source. More...
def	transformMags
	Transform brightness. More...
def	propagateFluxErrors

Static Public Attributes
tuple	primary = Field(dtype=str, doc="name of primary filter")
tuple	secondary = Field(dtype=str, doc="name of secondary filter")
tuple	c0 = Field(dtype=float, default=0.0, doc="Constant parameter")
tuple	c1 = Field(dtype=float, default=0.0, doc="First-order parameter")
tuple	c2 = Field(dtype=float, default=0.0, doc="Second-order parameter")

Detailed Description

Colorterm correction for one pair of filters.

The transformed magnitude p' is given by p' = primary + c0 + c1*(primary - secondary) + c2*(primary - secondary)**2

To construct a Colorterm, use keyword arguments: Colorterm(primary=primaryFilterName, secondary=secondaryFilterName, c0=c0value, c1=c1Coeff, c2=c2Coeff) where c0-c2 are optional. For example (omitting c2): Colorterm(primary="g", secondary="r", c0=-0.00816446, c1=-0.08366937)

This is subclass of Config. That is a bit of a hack to make it easy to store the data in an appropriate obs_* package as a config override file. In the long term some other means of persistence will be used, at which point the constructor can be simplified to not require keyword arguments. (Fixing DM-2831 will also allow making a custom constructor).

Definition at line 39 of file colorterms.py.

Member Function Documentation

def lsst.pipe.tasks.colorterms.Colorterm.propagateFluxErrors	(		self,
			primaryFluxErr,
			secondaryFluxErr
	)

Definition at line 80 of file colorterms.py.

    def propagateFluxErrors(self, primaryFluxErr, secondaryFluxErr):
        return np.hypot((1 + self.c1)*primaryFluxErr, self.c1*secondaryFluxErr)