Quick Start

In this quick start guide, you will learn how to install fiasco, download the CHIANTI atomic database, build an HDF5 version of the database required by fiasco, and create an Ion object. To install fiasco, run the following command in the terminal,

$ pip install fiasco

This will install latest version of the package and all needed dependencies from the Python Package Index or PyPI.

Next, let’s create an Ion object representing Fe XVIII:

>>> import fiasco
>>> import astropy.units as u
>>> fe_18 = fiasco.Ion('Fe XVIII', 1*u.MK)  

After running this last line, you should see the following message:

No HDF5 database found at $HOME/.fiasco/chianti_dbase.h5. Build it now? [Y/n]

where $HOME will be replaced by the path to your home directory. Press “y” to confirm that you want the built database to have this filename.

Note

If you want to build the database in a different directory, see Build the HDF5 Database in a Different Location.

Next, you should see the following message:

No CHIANTI database found at $HOME/.fiasco/chianti_dbase. Download it from http://download.chiantidatabase.org/CHIANTI_v8.0.7_database.tar.gz? [y/N]

Press “y” to download this version of the CHIANTI database to this directory. Once you confirm, you should see a progress bar indicating the progress of the download of the tar file containing all the files in the CHIANTI database. This step should take about a minute or so.

Note

If you want to download the database to a different directory or use an existing copy of the database, see Download the CHIANTI Database.

You should then see a second progress bar indicating the progress of building the HDF5 database. This step may take a few minutes. The progress bar output should look something like the following:

|================================================| 265M/265M (100.00%)      1m 9s
|=======>----------------------------------------| 496 /3.0k (16.06%) ETA  1m34s

These two steps together may take several minutes, but you will only need to do this once. fiasco will now look in $HOME/.fiasco/chianti_dbase.h5 for the built HDF5 version of the database. You can confirm this by looking at the default values read from the configuration file:

>>> fiasco.defaults  
{'ascii_dbase_root': PosixPath('.../.fiasco/chianti_dbase'),
 'hdf5_dbase_root': PosixPath('.../.fiasco/chianti_dbase.h5')}

Now that you have your database, you can use your ion object that you created above to access information about Fe XVIII:

>>> fe_18  
CHIANTI Database Ion
---------------------
Name: Fe 18
Element: iron (26)
Charge: +17
Number of Levels: 337
Number of Transitions: 7712

Temperature range: [1.000 MK, 1.000 MK]

HDF5 Database: ...chianti_dbase.h5
Using Datasets:
   ioneq: chianti
   abundance: sun_coronal_1992_feldman_ext
   ip: chianti

You are now ready to use fiasco to access and compute derived quantities from the CHIANTI atomic database!