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The group list is the primary mechanism for accessing and interacting with your data. As data files are imported in ATHENA, each gets an entry in the group list. Data generated during the course of using ATHENA, such as copied or merged groups, also get placed in the group list.
Each group list entry consists of two parts, the label and the check button. The label contains text identifying the group. The default is for the label to be the same as the file name. Clicking with the left mouse button on a label makes that group the current group. The current group's label is highlighted with a light red color and its parameters are displayed in the main window. The current group is the one that gets plotted when the red plotting buttons are pressed.
The check button is used to mark the group. Marking, explained in detail in the next section, is one of the fundamental user interface features in ATHENA. Any feature of ATHENA that involves more than one group uses the mark buttons.
You can copy a group by hitting Control-y or by selecting “Copy group” from the Group menu. This makes an identical copy of the current group and places it at the end of the groups list. All parameters are identical and the data arrays in IFEFFIT are all copied -- only the IFEFFIT group name in different.
Copying is very useful for examining how changes in parameter values propagate through the data processing. You can make one or more copies, change particular data values, and overplot the results.
The process of comparing parameter values can be automated. In the Group menu, you'll find an option for “Copy series”. This opens the dialog shown below. You can select the parameter to increment from the drop-down menu. The next three entry boxes are for setting the grid of parameter values. When you click “Make copies”, the copies are made, the parameter values are incremented, the new groups are inserted into the group list, and they are renamed with useful labels. Finally a plot is made showing the differences between the copies with different parameter values.
The series copying dialog. In this example, a series of four copies with «e0» values incremented by 5 eV.
When a file is imported into ATHENA, the name of the file is used as the label in the group list. That's fine, but you can change the label by selecting “Rename group” from the Group menu, typing Control-l, or double clicking on an item in the group list. This replaces the echo area with a dialog for entering the new label for the group, shown here.
Renaming a group list entry.
Hitting Return or clicking the OK button renames the group, shown here.
After renaming a group list entry.
We have already seen how groups can be copied. Making one or more copies is an excellent tool for exploring the effects of the various parameters in the main window.
There are several other useful tools for modifying the contents of the group list. You can reorder the items in the groups list using Alt-k or Alt-j to move the current group up or down in the list.
Hitting Control-k or Control-j changes the current group to the one above or below.
Items can be removed from the list. The current group or the marked groups can be removed from the project by selecting “Remove group” or “Remove marked groups” from the Group menu. You can remove all the groups from the list by selecting “Close project” from the File or Group menu or by hitting Control-w.
Hitting Control-b displays several pieces of information about the current group. The dialog that pops up to display that information is shown here.
The dialog containing information about the data group.
Hitting Control-B displays that information for all the marked groups.
If you mistakenly import a data group as the wrong record type, you can change it by selecting “Change record type” from the Group menu. You can only change between the various record types in energy, though. If you import a χ(k) file as μ(E) , you will have to remove the group and re-import it.
The dialog for changing the record type of a group.
You can turn on automated replotting when you select a new group by clicking on it in the group list, by selecting one of the items from the “Group replot” submenu at the bottom of the Plot menu, shown below. With one of the options from that submenu selected, groups will be replotted when you click on them.
Setting up group replotting from a submenu under the Plot menu.
If you right click on any item in the group list, a context menu is posted, as shown below. The top two items in that context menu are for plotting. They work just like the red and purple plot buttons. The second two items are the same as the Group and Values menu.
Clicking the right mouse button on a group list entry pops up this context menu.
As mentioned above, double clicking on a group list item will rename it.
Detector groups are group list entries that can only be plotted in energy. They are made from the numerator and denominator arrays that were used to make the data in the data group. When you choose “Make detector groups” from the Group menu, those two groups are added to the group list. Their «plot multiplier» parameters are set such they plot nicely with μ(E) from their original data group. Detector groups can only be made in the session during which the original data was imported. Insufficient information is saved to project files to be able to properly reconstruct the detector groups. You can plot the I0 array without making a detector group at any time from the Plot menu.
Background groups are group list entries that can be plotted in any space. A background group is created from the background function for a group when you choose “Make background group” from the Group menu. Creating a background group using a small «rbkg» parameter is one way to examine the atomic fine structure, or AXAFS, if you believe in such things.
