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Value Expressions

A value expression is a mathematical equation that returns a numeric (real or integer) result. The expression consists of a set of operators, functions and keywords. Value expressions are typically used in a network plot to proportionately size a network element based on the expression result.

A value expression may also be a multi-value expression. This is one where more than one value result is calculated, and is used to display and compare multiple values for a node or link. The expressions of a multi-value expressions are separated by a semi-colon ";".

Some example value expressions are as follows:

Centroids and Nodes

[node user data 1] ui1
[Initial boardings and final alightings] inboa;fiali

Links

[Link length] sqrt(sqr(xj-xi)+sqr(yj-yi))
[Auto Volume (in hundreds)] round(volau/100)

Transit Lines and Segments

[Transit vehicles per hour] 60/hdw