TreeTable view

The TreeTable view is pretty straightforward. It simply shows all the active
(not filtered out) objects in traditional table. Should one or more variables be used for grouping, then
the rows will be appropriately organized in a hierarchical manner. Clicking on table column header will
sort the column: the first click will sort ascending; the second click descending; the third click will
reset the data to the original order. To sort on multiple columns, you just press Ctrl key and hold while
clicking on the other columns. A number is displayed in the header to indicate the rank amongst the sorted
columns. Selected row in the TreeTable view will be displayed in the
TreeMap view
accordingly.