calibration

Calibration module for noise and flux.

class NoiseCalibrator(fname, comm=None, mpi_rank=0, add_varlss=False, no_eta=False)[source]

Bases: object

Noise calibration object.

\[i \rightarrow i / \eta,\]

where i is IVAR.

FITS file must have ‘VAR_FUNC’ extension. This extension must have columns for ‘lambda’ and ‘eta’. Wavelength array must be linearly and equally spaced. Uses cubic spline.

Parameters:

fname (str) – Filename to read by fitsio.
comm (None or MPI.COMM_WORLD, default: None) –
mpi_rank (int, default: 0) –
add_varlss (bool, default: False) – Use var_lss as an additive correction to noise in observed frame. Requires continuum.
no_eta (bool, default: False) – Turns off eta scaling by using eta=1.

eta_interp

Eta interpolator.

Type:: FastCubic1DInterp

_read(fname)[source]

apply(spectra_list)[source]

Apply the noise calibration by only scaling forestivar. Smooth component must be set after this.

Parameters:: spectra_list (list(Spectrum)) – Spectrum objects to noise calibrate.

class FluxCalibrator(fname, comm=None, mpi_rank=0)[source]

Bases: object

Flux calibration object.

\[ \begin{align}\begin{aligned}f &\rightarrow f / s\\i &\rightarrow i \times s^2,\end{aligned}\end{align} \]

where i is IVAR and s is the stacked flux.

FITS file must have ‘STACKED_FLUX’ extension. This extension must have columns for ‘lambda’ and ‘stacked_flux’. Wavelength array must be linearly and equally spaced. Uses linear interpolation.

Parameters:

fname (str) – Filename to read by fitsio.
comm (None or MPI.COMM_WORLD, default: None) –
mpi_rank (int, default: 0) –

flux_interp

Flux interpolator.

Type:: FastLinear1DInterp

_read(fname)[source]

apply(spectra_list)[source]

Apply the flux calibration by only scaling forestflux and forestivar. Smooth component must be set after this.

Parameters:: spectra_list (list(Spectrum)) – Spectrum objects to flux calibrate.

Arguments

add_calibration_parser(parser=None)[source]

Adds calibration related arguments to parser. These arguments are grouped under ‘Noise and flux calibation options’.

Parameters:: parser (argparse.ArgumentParser, default: None) –
Returns:: parser
Return type:: argparse.ArgumentParser

usage: foo [-h] [--noise-calibration NOISE_CALIBRATION]
           [--varlss-as-additive-noise] [--flux-calibration FLUX_CALIBRATION]

Noise and flux calibation options

--noise-calibration

Noise calibration file.

--varlss-as-additive-noise

var_lss as additive noise term after continuum fitting.

Default: False

--flux-calibration

Flux calibration file.