mangadap.par.emissionmomentsdb module

Container class for the database of emission-line bandpass filters used for non-parameteric measurements of emission-line flux and velocity moments.

Todo

Combine this with the main emissionlinemoments.py file.

Class usage examples

Emission-line moment databases are defined using SDSS parameter files. To define a database, you can use one of the default set of available emission-line moment databases:

from mangadap.par.emissionmomentsdb import EmissionMomentsDB
print(EmissionMomentsDB.available_databases())
elmom = EmissionMomentsDB.from_key('ELBMPL9')

The above call uses the EmissionMoments.from_key() method to define the database using its keyword and the database provided with the MaNGA DAP source distribution. You can also define the database directly for an SDSS-style parameter file:

from mangadap.par.emissionmomentsdb import EmissionMomentsDB
elmom = EmissionMomentsDB('/path/to/emission/moments/database/myelm.par')

The above will read the file and set the database keyword to ‘MYELM’ (i.e., the capitalized root name of the *.par file). See Emission-Line Measurements for the format of the parameter file.

Revision history

17 Mar 2016: Original implementation by K. Westfall (KBW)
11 May 2016: (KBW) Switch to using pydl.pydlutils.yanny and pydl.goddard.astro.airtovac instead of internal functions
06 Oct 2017: (KBW) Add function to return channel names.
02 Dec 2019: (KBW) Significantly reworked to use the new base class.
License

Copyright © 2019, SDSS-IV/MaNGA Pipeline Group

class mangadap.par.emissionmomentsdb.EmissionMomentsDB(parfile)[source]

Bases: mangadap.par.spectralfeaturedb.SpectralFeatureDB

Basic container class for the database of emission-line moments to calculate.

Each row of the database is parsed using mangadap.proc.bandpassfilter.BandPassFilterPar. For the format of the input file, see Non-parametric Emission-Line Measurements.

The primary instantiation requires the SDSS parameter file with the bandpass data. To instantiate using a keyword (and optionally a directory that holds the parameter files), use the mangadap.par.spectralfeaturedb.SpectralFeatureDB.from_key() class method. See the base class for additional attributes.

Parameters:parfile (str) – The SDSS parameter file with the database.
key

Database signifying keyword

Type:str
file

File with the data

Type:str
size

Number of features in the database.

Type:int
dummy

Boolean array flagging bandpasses as dummy placeholders.

Type:numpy.ndarray
_parse_yanny()[source]

Parse the yanny file (provided by file) for the emission-line moment database.

Returns:The list of mangadap.par.parset.ParSet instances for each line of the database.
Return type:list
channel_names(dicttype=True)[source]

Return a dictionary with the channel names as the dictionary key and the channel number as the dictionary value. If dicttype is False, a list is returned with just the string keys.

default_data_dir = 'emission_bandpass_filters'