Index History

It is common that whilst browsing through a set of expression profiles, one is struck by the thought, 'hmmm, but how about the expression of this gene...', which then leads one to looking up the expression, which hopefully will provide some insight. In order to allow users to do this without losing their current browsing position the program remembers the last 20 probe set selections made, and the last browsing position of the user. These can be accessed from the index history window (see below) which in addition to allowing the user to go back to his/hers earlier browsing position also allows the user to make boolean selections of the past 20 selections.

Figure 1. Index History Window. This window contains a set of widgets (maximum 20) which represent one probe set selection each in addition to some controls which allow combinations of selections to be made. Each index widget contains a numerical identifier, a load button, a label indicating the number of probe sets in the selection, a text description indicating how the selection was made, an include selector and and exclude selector.

The history index window has three primary functions:

1. Resumption of interrupted sessions. Pressing the load button on an index widget will cause the application to reload the old index and return the user to the last visited probe set (bit heavy on the metaphors).
2. Making simple combinations of past selections through selecting the include (left) or exclude check boxes in the appropriate index widgets. The size of the resulting probe sets is automatically updated and displayed underneath the include/exclude check boxes. Pressing the 'Load Combination' button causes the resulting index to be loaded.
3. Creating boolean combinations of past selections. The boolean statement is input in the bottom text input window. Past selections are denoted by their numerical identifiers, brackets, & (and), | (or), ! (not). Hence '1 & 2' indicates probe sets present in both selections 1 and 2 whereas '1 | 2' indicates probe sets present in either. The boolean expression can be arbitrarily complex and include many layers of bracketing allowing for a nice flexibility. The size of the resulting combination can be evalueated by pressing the 'Eval' button and loaded with the 'Load' button. Note that loading a boolean combination will creates a new entry in the index history window, and results in the numbers changing (this is not a particularly nice behaviour, and should ideally be changed to something better (unique ids perhaps?)).