lsst.pipe.tasks  21.0.0-119-g1a9a5132+a9a472b1ca
Public Member Functions | Static Public Attributes | List of all members
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 getCorrectedMagnitudes (self, refCat, filterName="deprecatedArgument")
 
def transformSource (self, source)
 Transform the brightness of a source. More...
 
def transformMags (self, primary, secondary)
 Transform brightness. More...
 
def propagateFluxErrors (self, primaryFluxErr, secondaryFluxErr)
 

Static Public Attributes

 primary = Field(dtype=str, doc="name of primary filter")
 
 secondary = Field(dtype=str, doc="name of secondary filter")
 
 c0 = Field(dtype=float, default=0.0, doc="Constant parameter")
 
 c1 = Field(dtype=float, default=0.0, doc="First-order parameter")
 
 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 40 of file colorterms.py.

Member Function Documentation

◆ getCorrectedMagnitudes()

def lsst.pipe.tasks.colorterms.Colorterm.getCorrectedMagnitudes (   self,
  refCat,
  filterName = "deprecatedArgument" 
)
Return the colorterm corrected magnitudes for a given filter.

Parameters
----------
refCat : `lsst.afw.table.SimpleCatalog`
    The reference catalog to apply color corrections to.
filterName : `str`, deprecated
    The camera filter to correct the reference catalog into.
    The ``filterName`` argument is unused and will be removed in v23.

Returns
-------
RefMag : `np.ndarray`
    The corrected AB magnitudes.
RefMagErr : `np.ndarray`
    The corrected AB magnitude errors.

Raises
------
KeyError
    Raised if the reference catalog does not have a flux uncertainty
    for that filter.

Notes
-----
WARNING: I do not know that we can trust the propagation of magnitude
errors returned by this method. They need more thorough tests.

Definition at line 62 of file colorterms.py.

◆ propagateFluxErrors()

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

Definition at line 141 of file colorterms.py.

◆ transformMags()

def lsst.pipe.tasks.colorterms.Colorterm.transformMags (   self,
  primary,
  secondary 
)

Transform brightness.

    @param[in] primary  brightness in primary filter (magnitude)
    @param[in] secondary  brightness in secondary filter (magnitude)
    @return the transformed brightness (as a magnitude)

Definition at line 131 of file colorterms.py.

◆ transformSource()

def lsst.pipe.tasks.colorterms.Colorterm.transformSource (   self,
  source 
)

Transform the brightness of a source.

    @param[in] source  source whose brightness is to be converted; must support get(filterName)
                (e.g. source.get("r")) method, as do afw::table::Source and dicts.
    @return the transformed source magnitude

Definition at line 122 of file colorterms.py.

Member Data Documentation

◆ c0

lsst.pipe.tasks.colorterms.Colorterm.c0 = Field(dtype=float, default=0.0, doc="Constant parameter")
static

Definition at line 58 of file colorterms.py.

◆ c1

lsst.pipe.tasks.colorterms.Colorterm.c1 = Field(dtype=float, default=0.0, doc="First-order parameter")
static

Definition at line 59 of file colorterms.py.

◆ c2

lsst.pipe.tasks.colorterms.Colorterm.c2 = Field(dtype=float, default=0.0, doc="Second-order parameter")
static

Definition at line 60 of file colorterms.py.

◆ primary

lsst.pipe.tasks.colorterms.Colorterm.primary = Field(dtype=str, doc="name of primary filter")
static

Definition at line 56 of file colorterms.py.

◆ secondary

lsst.pipe.tasks.colorterms.Colorterm.secondary = Field(dtype=str, doc="name of secondary filter")
static

Definition at line 57 of file colorterms.py.


The documentation for this class was generated from the following file: