Color

class lsst.pipe.tasks.functors.Color(col, filt2, filt1, **kwargs)

Bases: lsst.pipe.tasks.functors.Functor

Compute the color between two filters

Computes color by initializing two different Mag functors based on the col and filters provided, and then returning the difference.

This is enabled by the _func expecting a dataframe with a multilevel column index, with both 'band' and 'column', instead of just 'column', which is the Functor default. This is controlled by the _dfLevels attribute.

Also of note, the default dataset for Color is forced_src', whereas for Mag it is 'meas'.

Parameters:

col : str

Name of flux column from which to compute; same as would be passed to lsst.pipe.tasks.functors.Mag.

filt2, filt1 : str

Filters from which to compute magnitude difference. Color computed is Mag(filt2) - Mag(filt1).

Attributes Summary

columns	Columns required to perform calculation
filt
name	Full name of functor (suitable for figure labels)
noDup
shortname	Short name of functor (suitable for column name/dict key)

Methods Summary

__call__(data[, dropna])	Call self as a function.
difference(data1, data2, **kwargs)	Computes difference between functor called on two different ParquetTable objects
fail(df)
multilevelColumns(parq, **kwargs)	Returns columns needed by functor from multilevel dataset

Attributes Documentation

columns

Columns required to perform calculation

filt

name

Full name of functor (suitable for figure labels)

noDup

shortname

Short name of functor (suitable for column name/dict key)

Methods Documentation

__call__(data, dropna=False)

Call self as a function.

difference(data1, data2, **kwargs)

Computes difference between functor called on two different ParquetTable objects

fail(df)

multilevelColumns(parq, **kwargs)

Returns columns needed by functor from multilevel dataset

To access tables with multilevel column structure, the MultilevelParquetTable or DeferredDatasetHandle need to be passed either a list of tuples or a dictionary.

Parameters:

data : MultilevelParquetTable or DeferredDatasetHandle

columnIndex (optional): pandas `Index` object

either passed or read in from DeferredDatasetHandle.

`returnTuple` : bool

If true, then return a list of tuples rather than the column dictionary specification. This is set to True by CompositeFunctor in order to be able to combine columns from the various component functors.