rail.core.utilPhotometry module

Module that implements operations on photometric data such as magnitudes and fluxes.

class rail.core.utilPhotometry.HyperbolicMagnitudes(args, comm=None)

Bases: PhotormetryManipulator

Convert a set of classical magnitudes to hyperbolic magnitudes (Lupton et al. 1999). Requires input from the initial stage (HyperbolicSmoothing) to supply optimal values for the smoothing parameters (b).

Configuration Parameters: output_mode [str]: What to do with the outputs (default=default) value_columns [list]: list of columns that prove photometric measurements (fluxes or magnitudes) (default=[‘mag_u_lsst’, ‘mag_g_lsst’, ‘mag_r_lsst’, ‘mag_i_lsst’, ‘mag_z_lsst’, ‘mag_y_lsst’]) error_columns [list]: list of columns with errors corresponding to value_columns (assuming same ordering) (default=[‘mag_err_u_lsst’, ‘mag_err_g_lsst’, ‘mag_err_r_lsst’, ‘mag_err_i_lsst’, ‘mag_err_z_lsst’, ‘mag_err_y_lsst’]) zeropoints [list]: optional list of magnitude zeropoints for value_columns (assuming same ordering, defaults to 0.0) (default=[]) is_flux [bool]: whether the provided quantities are fluxes or magnitudes (default=False)

compute(data, parameters)

Main method to call. Outputs hyperbolic magnitudes compuated from a set of smoothing parameters and input catalogue with classical magitudes and their respective errors.

Parameters:

• data (PqHandle) – Input table with photometry (magnitudes or flux columns and their respective uncertainties) as defined by the configuration.

• parameters (PqHandle) – Table with smoothing parameters per photometric band, determined by HyperbolicSmoothing.

Returns:

output – Output table containting hyperbolic magnitudes and their uncertainties. If the columns in the input table contain a prefix mag_, this output tabel will replace the prefix with hyp_mag_, otherwise the column names will be identical to the input table.

Return type:

PqHandle

config_options = {'error_columns': <ceci.config.StageParameter object>, 'is_flux': <ceci.config.StageParameter object>, 'output_mode': <ceci.config.StageParameter object>, 'value_columns': <ceci.config.StageParameter object>, 'zeropoints': <ceci.config.StageParameter object>}

inputs = [('input', <class 'rail.core.data.PqHandle'>), ('parameters', <class 'rail.core.data.PqHandle'>)]

name = 'HyperbolicMagnitudes'

outputs = [('output', <class 'rail.core.data.PqHandle'>)]

run()

Compute hyperbolic magnitudes and their error based on the parameters determined by HyperbolicSmoothing.

class rail.core.utilPhotometry.HyperbolicSmoothing(args, comm=None)

Bases: PhotormetryManipulator

Initial stage to compute hyperbolic magnitudes (Lupton et al. 1999). Estimates the smoothing parameter b that is used by the second stage (HyperbolicMagnitudes) to convert classical to hyperbolic magnitudes.

Configuration Parameters: output_mode [str]: What to do with the outputs (default=default) value_columns [list]: list of columns that prove photometric measurements (fluxes or magnitudes) (default=[‘mag_u_lsst’, ‘mag_g_lsst’, ‘mag_r_lsst’, ‘mag_i_lsst’, ‘mag_z_lsst’, ‘mag_y_lsst’]) error_columns [list]: list of columns with errors corresponding to value_columns (assuming same ordering) (default=[‘mag_err_u_lsst’, ‘mag_err_g_lsst’, ‘mag_err_r_lsst’, ‘mag_err_i_lsst’, ‘mag_err_z_lsst’, ‘mag_err_y_lsst’]) zeropoints [list]: optional list of magnitude zeropoints for value_columns (assuming same ordering, defaults to 0.0) (default=[]) is_flux [bool]: whether the provided quantities are fluxes or magnitudes (default=False)

compute(data)

Main method to call. Computes the set of smoothing parameters (b) for an input catalogue with classical photometry and their respective errors. These parameters are required by the follow-up stage HyperbolicMagnitudes and are parsed as tabular data.

Parameters:

data (PqHandle) – Input table with magnitude and magnitude error columns as defined in the configuration.

Returns:

parameters – Table with smoothing parameters per photometric band and additional meta data.

Return type:

PqHandle

config_options = {'error_columns': <ceci.config.StageParameter object>, 'is_flux': <ceci.config.StageParameter object>, 'output_mode': <ceci.config.StageParameter object>, 'value_columns': <ceci.config.StageParameter object>, 'zeropoints': <ceci.config.StageParameter object>}

inputs = [('input', <class 'rail.core.data.PqHandle'>)]

name = 'HyperbolicSmoothing'

outputs = [('parameters', <class 'rail.core.data.PqHandle'>)]

run()

Computes the smoothing parameter b (see Lupton et al. 1999) per photometric band.

class rail.core.utilPhotometry.PhotormetryManipulator(args, comm=None)

Bases: RailStage, ABC

Base class to perform opertations on magnitudes. A table with input magnitudes and errors is processed and transformed into an output table with new magnitudes and errors.

Subclasses must implement the run() and compute() method.

abstract compute(data)

Main method to call.

Parameters:

data (PqHandle) – Input tabular data with column names as defined in the configuration.

Returns:

output – Output tabular data.

Return type:

PqHandle

config_options = {'error_columns': <ceci.config.StageParameter object>, 'is_flux': <ceci.config.StageParameter object>, 'output_mode': <ceci.config.StageParameter object>, 'value_columns': <ceci.config.StageParameter object>, 'zeropoints': <ceci.config.StageParameter object>}

get_as_fluxes()

Loads specified photometric data as fluxes, converting magnitudes on the fly.

inputs = [('input', <class 'rail.core.data.PqHandle'>)]

name = 'PhotormetryManipulator'

outputs = [('output', <class 'rail.core.data.PqHandle'>)]

abstract run()

Implements the operation performed on the photometric data.