Posted on July 04, 2008
An (information) visualization application must handle a huge amount of data, and should also let user do quick interaction to find out desired information (or to filter out undesired one). Hence, such dynamic query or data query is a very critical task for visualization.
For such reason prefuse provides a query expression language to do those tasks. The Expression can be used to query Data Tables (like SQL in database) for informational attributes, and it can also be used to query Visual Abstraction, i.e. a visual item, for the visual attributes.
Following figure shows all possible Expressions.
- There are expressions for doing string, math and Boolean operations.
- Expressions in prefuse.visual.expression are for querying on visual item (Visual Abstraction) . For example, an expression to decide if a visual item visible or not.
Some Expressions are treated as Function.
Some Expressions are treated as Predicate which be always evaluated as true or false.
1 comments:
This is great. Please continue!
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