build_lbda_from_config

build_lbda_from_config(config)

Build wavelength coordinates from a configuration dictionary.

Parameters:

config (dict) –

Spectrograph configuration dictionary. The following keys are used:

• "spectral_range": (wmin, wmax) in Angstrom.

• "dispersion_law": ecsv file with wavelength and offset (in pix) columns. If given, it defines the wavelength solution.

• "dispersion_scale": scaling applied to the dispersion law (default 1).

• "spectral_resolution": resolving power, used if no "dispersion_law" is given.

• "dispersion_resolution": number of pixels per resolution element (default 2.1).

Returns:

• lbda (numpy.ndarray) – Mid-bin wavelengths, in Angstrom.

• lbda_edges (numpy.ndarray) – Bin edge wavelengths, in Angstrom.

Raises:

ValueError – If neither "spectral_resolution" nor "dispersion_law" is set.