associate_cals

ndmapper.calibrations.associate_cals(cals, inputs, cal_type, from_type=None, cal_dict=None)

Associate a given type of processed calibrations with the data they will subsequently be used to calibrate (both as DataFile instances).

cals : DataFileList or DataFile or dict

A list/dict of processed calibrations, available for association with zero or more matching inputs. These are normally DataFile instances but, in the case of a dictionary, the values can also be objects of some other type (such as a list of background regions). If a dict is provided, with filename strings as the keys, calibrations are retrieved from it directly, using the names determined by calibration dictionary (or self) matching, otherwise such a dictionary is created internally from the supplied DataFile instances, keyed by their filenames. An entry must exist in cals for every match to inputs found in cal_dict.

inputs : DataFileList or DataFile

DataFile instances with which processed calibrations are to be associated. If no calibration match can be determined from cal_dict for a given input, the association is silently omitted (but it is an error for a calibration that is matched to be missing from cals).

cal_type : str

Associated calibration type; this determines the name of the key (eg. ‘flat’ or ‘trace’) under which the calibrations get associated in the cals dictionaries of the inputs. It must match a type name expected by later processing steps, rather than a type name defined in the calibration dictionary (though these are typically the same).

from_type : str, optional

Calibration dictionary type to associate, if different from the default of cal_type. This can be used for multiple purposes, including: 1. re-use of, for example, an associated ‘flat’ in the calibration dictionary (where available) as a ‘trace’ reference for spectral extraction; 2. when the type naming convention from a calibration look-up differs from that expected by subsequent processing steps (eg. due to different authors) and 3. associating calibration files with themselves (a case that may or may not exist explicitly in the calibration dictionary). The special parameter value of ‘self’ causes the cal_dict look-up to be skipped altogether and, for each input file, looks for a file in cals with the same original name. In case 1, where no substitute association exists, an entry (‘trace’) must be added manually to the calibration dictionary, pointing to either an existing calibration name label or a new one.

cal_dict : dict, optional

A populated calibration dictionary, in the specific format produced by init_cal_dict() or services.look_up_cals(), used to match cals with the inputs. Must be provided unless from_type== 'self'.