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There is a feature that ATHENA shares with almost any other computer program -- not just analysis programs, but any program. Soon after starting to use ATHENA, you will do something silly and regrettable. Often this is as simple as changing a parameter to some bad value and forgetting what the good value was. To help mitigate this sort of problem, ATHENA allows you to freeze data groups.
A frozen group is one for which you cannot change its parameter values. When a group is frozen, the entry boxes associated with parameters become deactivated, which means that it is impossible to type in them. Furthermore, any global action such as constraining parameters or using the alignment dialog, will have no effect on the frozen group.
The idea behind frozen groups is that, after working for a while to find parameter values that you like, you can freeze the group to avoid inadvertently altering its parameters. The various group freezing functions can be found in the Values menu, as shown in the screenshot below.
The frozen groups submenu is found under the Values menu. Several visual cues indicate that a group is frozen, including the green highlighting the group list and the use of italic text in the main menu.
The “Freeze groups” submenu offers a number of ways of selecting which groups to freeze. The frozen state of the current group can be toggled by typing Control-f and all groups can be frozen or unfrozen by typing Control-F or Control-U. You can also freeze or unfreeze all marked groups. Finally, you can mark or unmark all groups using regular expressions. This works in the same manner using regular expressions to mark groups.
There are various visual changes when a group is frozen. The highlight color in the group list changes from light red to light green. The text in the group list becomes italic. The labels for each section of parameters in the main window becomes italic. Finally, the label in the main window that normally says “Current group” is changed to “Frozen group”.
When a group is frozen, direct edits of parameter values are disallowed. Frozen groups are skipped for algorithmic edits, such as parameter constraints or alignment. You can, however, still remove a frozen group from the project. Unfreezing a group is a simple as hitting Control-f again.
