Command line functions
SPEDAS can be used in two ways:
- The IDL command line
- The SPEDAS GUI
Comparing the two, the command line is more powerful, it offers more options, and there are functions that have only command line representation without any equivalent GUI element. On the other hand, new users may find the GUI easier to work with.
To use the IDL command line, an IDL software license from Exelis (now Harris Geospatial) is required.
When working with SPEDAS, the workflow is usually the following:
- Load some data.
- Perform some transformations on the data.
- Make some plots.
-- Load data --
SPEDAS can download data from several space missions. Each mission provides its own functions to load data. Each mission has its own directory in the "projects" folder and this directory contains the functions needed to load data. The files contain detailed information on the command line functions needed to load particular data and the parameters and keywords that the user can provide. Most of the time the user has to provide as paramenters the dates and the instruments for which data should be loaded.
For example, to load FGM data for the probe 1 of the MMS mission, the command is:
mms_load_fgm, probe=1, trange=['2015-09-01/00:00:00', '2015-09-02/00:00:00'], level='l2'
This command line function will download the proper CDF files from a remote directory, read the files and load the data into an IDL object that is called tplot. This object is the heart of SPEDAS, it will hold all the data and it can be used to manipulate and plot the data.
The new SPEDAS user has several options in order to find the relevant load functions:
- Open the projects directory, find the load file and read the comments at the beginning of the file.
- Open the examples directory of a particular project and find a crib sheet to use as an example.
- Browse or search the SPEDAS HTML documentation.
-- Data analysis --
-- Plots --