Cube voyager

Infobox Software
name = Cube Voyager



caption =
author =
developer = Citilabs, Inc. [http://www.citilabs.com]
released =
latest release version = 5.0.1
latest release date = June 23, 2008
latest preview version =
latest preview date =
programming language =
operating system = Windows 2000, Windows XP, Windows Vista
platform =
language =
status =
genre = transportation forecasting
license =
website =

Cube Voyager is the name of a software package produced by Citilabs [http://www.citilabs.com] for transportation forecasting. Cube Voyager permits analysts to code models of travel demand and transportation supply using a simple scripting language that automates complex network and matrix calculations. Modular program "steps" are linked together into model "applications" which can be run iteratively with feedback to find transportation supply/demand equilibrium solutions for alternative future scenarios as well as existing conditions.

Scripting Syntax

Cube Voyager is also the name of the scripting language with which Cube users develop models and manipulate data. The language has a simple syntax based upon sequential processing of control statements from a script or job file. [Cube Voyager Reference Guide, Citilabs, Inc., 2007-2008] Each statement contains at most one control word (also referred to as a "command" followed by one or more keywords. Each keyword is then paired with one or more numeric or string values using the equals sign "=", which is used as an assignment operator. The language is free-format and case insensitive, and continuation characters such as commas may be used to extend long statements over multiple lines. Text following the semi-colon ";" character on a line is interpreted as a comment, and multi-line comments can also be inserting "/*" before and "*/" after the text to be ignored by the processor.

Program Modules

In addition to the "Pilot" module for general computations and process flow control, Cube Voyager includes multiple special-purpose modules that perform common tasks involved in transportation forecasting, such as:

* Trip generation
* Trip distribution
* Fratar (iterative proportional matrix fitting)
* Matrix processing (including logit and mode choice modeling)
* Public transport (PT) system analysis
* Highway route assignment including intersection modeling based on Highway Capacity Manual standards
* Network pre- and post-processing

Key to the processing logic of these modules is the concept of user-defined control statement "stacks" which are repeated for each link or zone in a network of interest. Some of these modules, such as Fratar, Distribution, Highway, and PT, also iteratively compute solutions to equilibrium network or matrix optimization sub-problems. Due to the user-controlled nature of the Cube Voyager scripting environment the exact nature of the algorithms implemented may be quite varied.

Supported Data Formats

In addition to open structured plain text formats such as CSV, Cube Voyager can read and write matrices and networks in a proprietary binary format that is optimized for efficient data access. Cube Voyager is also designed for seamless exchange and tight integration with an ESRI-based geographic information system (GIS), and can read and write data in shapefile, xBase, and personal geodatabase formats.

References