trident.line_database.LineDatabase.parse_subset_to_ions

LineDatabase.parse_subset_to_ions(subsets=None)[source]

Select ions based on those needed to create specific lines. Once you’ve created a LineDatabase, you can subselect certain ions from it based on the line characteristics of atom, ion state, identifier, and/or wavelength. Similar to parse_subset but outputs a list of ion tuples (e.g. (‘H’, 1), (‘Fe’, 2)), instead of a list of Line objects.

Will return the unique union of all ions matching the specified subsets from the LineDatabase.

Parameters

Subsets

list of strings, optional

List strings matching possible lines. Strings can be of the form: * Atom - Examples: “H”, “C”, “Mg” * Ion - Examples: “H I”, “H II”, “C IV”, “Mg II” * Line - Examples: “H I 1216”, “C II 1336”, “Mg II 1240” * Identifier - Examples: “Ly a”, “Ly b”

If set to None, selects ions necessary to produce all lines in LineDatabase. Default: None

Returns

Ion subset

list of ion tuples

A list of the ions necessary to produce the desired lines Each ion tuple is of the form (‘H’, 1) = neutral hydrogen

Example

Get a list of all ions necessary to generate lines for Carbon, Mg II and Lyman alpha

>>> ldb = LineDatabase('lines.txt')
>>> ions = ldb.parse_subset_to_ions(['C', 'Mg II', 'H I 1216'])
>>> print(ions)