the prefuse visualization toolkit

ExpressionParser does not support if-statements. See http://prefuse.org/doc/api/prefuse/data/expression/parser/ExpressionParser.html for a good listing of what is supported.

What about using "AND" to concatenate both expressions, as you have spoken yourself?

> only display edges with non-zero degrees and edges with a weight attribute greater than a certain amount

hope that helps, Björn