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QUOGGLES - FAQ

The following list answers frequently asked questions:
When scrolling the main panel, the input box(es) do not move?
This does not influence the connection between the standard input box and the next box as long as the corresponding marker is green.

The query does not work as expected?
Most problems can be solved by looking at the type of some box's output. Some errors occur because the box yields a collection of sets (of out-edges, for example) and not a collection (of edges) as maybe expected. try adding some Output_Boxes at critical places, moving those boxes that cause the problems aside.

A box cannot be (re)moved since other boxes are always marked instead?
Sometimes, if there are several boxes close together, the bounding box of some boxes prevent that smaller ones can be marked. The solution is to temporarily move the neighboring boxes aside.

How can the input box at the left hand side of the window be removed?
The standard input box can neither be removed nor replaced.

Sometimes, a second input box appears below the standard input box?
The implementation features a second standard input box that produces the set of graph elements selected in the current graph. This box appears only if there is an active selection in the corresponding Gravisto view that displays the current graph. After the execution of a query, the QUOGGLES system removes any selection to enable the user to select the desired parts in the result table.

The space in the main panel does not suffice for the query?
There should be enough room for any human generated query in the main panel! If the query reaches the top of the window, try dragging the whole query some distance down and connect it to the input box with a OneOneConnector_Box. If that does not help, consider moving some part of the query into a SubQuery_Box.

When creating a OneOneConnector_Box, it suddenly disappears?
Try drawing it from left to right.

How to start a connector at an output having already an Output_Box?
Currently, the only way is to temporarily move away the Output_Box, drag the OneOneConnector_Box and move Output_Box back.

Can a query be saved into different formats?
Currently, only an extended GML format is supported.

Can the contents of a saved subquery be added to the current query?
Currently, no. Except for loading the subquery into a SubQuery_Box.

Despite of a large query having been executed, the result table is empty?
There are three possibilities for this: First, it might be that there are no Output_Boxes present in the query. Only data marked by such a box is displayed in the result table. Second, all Output_Boxes are located at boxes that are not executed. Remember that boxes not reachable from any standard input box and not necessary for the execution of other boxes are not executed at all. And third, it might be that all present Output_Boxes have empty lists as the data they present in the result table.

Executing the same query several times yields different results?
If boxes like the ChangeAttribute_Box that can initiate changes in the current graph, subsequent execution of queries will indeed probably yield different results. Another possibility is that the second standard input box has been used and the selection in the current graph has changed since the last execution of the query.

After having written a new box, why is it not available?
The new box must be entered into the box description file "boxes.xml".


Last modified: Tue Feb 17 22:40:02 Westeuropäische Normalzeit 2004