Project files

Preserving the state of your analysis project

Save button, change indicator, update discussion of file format.

The most important type of output file is the project file. A project file contains all of the data you have imported, all of the parameters associated with each data file, the content of the journal, and several other collections of important data. All of this gets saved in a single, easily transportable file.

The primary purpose of the project file is to save you work. When you open a saved project file, all of the data and all of their parameters are imported into ATHENA, returning ATHENA to the state it was in when saved the project file. ARTEMIS (ATHENA's sister program intended for analysis of EXAFS data) can read these project files. Thus the project file is the best way of moving your data between the two programs.

Even better, the project file is a form of collaboration. The format of the file is platform independent. A project file written on one computer can read on another computer, even if those computers use different operating systems. A project file can be burned to a CD, placed on a web site, or sent to a collaborator by email.

To save a project file, simply select one of the File menu options highlighted in this figure.

The first two options saves the entire current state of ATHENA. If the project has already been saved, the “Save project” option overwrites the previous file with the new state of your project. Hitting Control-s does the same thing. Clicking on the modified indicator -- the other highlighted region in the screenshot -- also saves the project. Alternately, you can select “Save project as...” and you will be prompted for a new file name for the project.

The final option will write only the marked groups to a project file. You can think of this as a sort of “sub-project” file. This is another of the many ways that the group markings are used by ATHENA.

The “Save” button at the top of the screen will save the current project, prompting for a file name if needed. As you work with ATHENA. this button turns increasingly red, reminding you of the need to save your work early and often.

As with any software, you should save your work early and often. ATHENA and IFEFFIT have their flaws. It would be a shame to discover one of them after having done a lot of unsaved work.

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The project file format and compatibility with older versions

The ATHENA project file is designed to be quick and easy for ATHENA to read. Unfortunately, the file format is not particularly human-friendly. Most of the lines of the project file are in the form written out by perl's Data::Dumper module. This freezes ATHENA's internal data structures into perl code. When the project file is imported, these lines of perl code are evaluated. (This evaluation is performed in a Safe compartment, i.e. a memory space with restricted access to perl's system functionality. This provides a certain level of protection against project files constructed with malicious intent.)

The project file is written using compression in the format of the popular gzip program using the highest level of compression, albeit without the common .gz file extension. Both ATHENA and ARTEMIS use these files.