mangadap.par.absorptionindexdb module¶

Container class for the database of absorption-line indices to measure.

License:

Copyright (c) 2015, SDSS-IV/MaNGA Pipeline Group: Licensed under BSD 3-clause license - see LICENSE.rst

Source location:

$MANGADAP_DIR/python/mangadap/par/absorptionindexdb.py

Imports and python version compliance:

from __future__ import division
from __future__ import print_function
from __future__ import absolute_import
from __future__ import unicode_literals

import sys
import warnings
if sys.version > '3':
    long = int

import os.path
import numpy

from pydl.goddard.astro import airtovac
from pydl.pydlutils.yanny import yanny
from .parset import ParDatabase
from .spectralfeaturedb import available_spectral_feature_databases, SpectralFeatureDBDef
from ..proc.bandpassfilter import BandPassFilterPar
from ..proc.util import select_proc_method

Class usage examples:

Absorption-line index databases are defined using SDSS parameter files. To define a database, you can use one of the default set of available absorption-line index databases (see available_absorption_index_databases()):

from mangadap.par.absorptionindexdb import AbsorptionIndexDB
p = AbsorptionIndexDB('LICK')

The above call requires that the $MANGADAP_DIR environmental variable is set. If it is not, you can define it’s location, as in:

from mangadap.par.absorptionindexdb import AbsorptionIndexDB
p = AbsorptionIndexDB('LICK', dapsrc='/path/to/dap/source')

Finally, you can create your own SDSS-style parameter file with your own absorption-line indices to use. Example files are provided in $MANGADAP_DIR/data/absorption_indices with a companion README file. With your own file, you have to point to the file using SpectralFeatureDBDef, which you can then pass to AbsorptionIndexDB:

from mangadap.par.spectralfeaturedb import SpectralFeatureDBDef
from mangadap.par.absorptionindexdb import AbsorptionIndexDB
d = SpectralFeatureDBDef(key='USER',
                         file_path='/path/to/parameter/file')
p = AbsorptionIndexDB('USER', indxdb_list=d)

The reference frame of the absorption-line index can be different for each index; a column in the SDSS parameter file is used to specify either air or vacuum wavelengths. When reading the input parameter file, AbsorptionIndexDB will convert the input index definition to vacuum on a case-by-case basis based on the SDSS parameter file entries, meaning AbsorptionIndexDB only provides vacuum wavelengths.

Revision history:

Mar 2016: Original implementation by K. Westfall (KBW)
May 2016: (KBW) Switch to using pydl.pydlutils.yanny and
pydl.goddard.astro.airtovac instead of internal functions
Dec 2016: (KBW) Relocated from proc to par.
Oct 2017: (KBW) Add function to return channel names

class mangadap.par.absorptionindexdb.AbsorptionIndexDB(database_key, indxdb_list=None, dapsrc=None)[source]¶

Bases: mangadap.par.parset.ParDatabase

Basic container class for the database of absorption-line index parameters. See mangadap.parset.ParDatabase for additional attributes.

Parameters:

database_key (str) – Keyword selecting the database to use.
indxdb_list (list) – (Optional) List of SpectralFeatureDBDef objects that define the parameters required to setup the absorption-line index database. The database_key must select one of the objects in this list.
dapsrc (str) – (Optional) Root path to the DAP source directory. If not provided, the default is defined by mangadap.config.defaults.dap_source_dir().

database¶

Database parameters.

Type:	`mangadap.par.ParSet`

nindx¶

Number of artifacts in the database

Type:	int

channel_names(offset=0)[source]¶

mangadap.par.absorptionindexdb.available_absorption_index_databases(dapsrc=None)[source]¶

Return the list of database keys and file names for the available absorption-line index databases. The currently available databases are:

KEY	N	Description
LICK	21	The standard Lick indices from Trager et al. (1998).
STANDARD	38	Includes additional Balmer and IMF-sensitive indices

This is a simple wrapper for mangadap.par.spectralfeaturedb.available_spectral_feature_databases().

Parameters:	dapsrc (str) – (Optional) Root path to the DAP source directory. If not provided, the default is defined by `mangadap.config.defaults.dap_source_dir()`.
Returns:	An list of `SpectralFeatureDBDef` objects, each of which defines a unique set of absorption-line indices (see `mangadap.proc.bandpassfilter.BandPassFilterPar`).
Return type:	list

Todo

Add backup function for Python 2.
Somehow add a python call that reads the databases and constructs the table for presentation in sphinx so that the text above doesn’t have to be edited with changes in the available databases.