Software

Features Easy to use graphical interface Extensive object model Microsoft Visual Basic syntax Comprehensive documentation Manipulation of agent collections User-defined coordinate systems Bounded rectangle, toroidal, and unbounded simulation topologies Fast neighbor search algorithms Powerful color management functionality User-defined properties Tools for simulation control and monitoring Leverage Microsoft Excel functionality Sample simulations included It's freeware!

What Does it Do?

VisualBots for Excel is an educational tool for exploring the fascinating world of multi-agent systems and their emergent behaviors. The VisualBots simulator can be used to create virtual worlds of programmable agents that interact with one another through time. The simulator is a ActiveX control that exposes objects, methods, and properties that are manipulated using the Visual Basic for Applications component of Microsoft Excel. The simulator consists of graphics window for viewing a simulation's progress through time and an easy to use user interface for starting, monitoring, and stopping simulations.

Easy to Learn

One of the advantages of developing the VisualBots object model in Microsoft Visual Basic is the ease with which agents can be manipulated in the visual, object-oriented programming environment of Visual Basic. The Visual Basic Editor, Object Browser, and technologies such as Microsoft's Intellisense make learning how to program using the VisualBots object model easy and fun.

The Players

There are two types of robots that live in the VisualBots world. One is a movable object called a "Bot" - multiple Bots can exists and interact within a simulation. The other type of robot is a stationary object called a "Cell" which occupies a rectangular area. Cells are arranged in a regular grid pattern covering the simulation space. Bot and Cell characteristics and behaviors are programmable at both individual and group levels. Group manipulation is facilitated through the use of collections, which are structures that associate the objects into groups with like properties and behaviors.

Simulation Control

VisualBots employs an object-oriented design for programming the simulator. The VisualBots object model is hierarchical, with the top level being the "World" object. The World object exposes the second level which consists of collections of agents. Each of these collections exposes a third level consisting of the individual agents. And lastly, individual Bots and Cells expose their own properties and methods.

Agent properties can be affected by the agent's evolution through time and history of interaction with other VisualBots objects. These properties include characteristics such as color, shape, age, direction, speed, and position. User-defined properties can be created and manipulated through the use of "Tag" objects, which can be attached to each agent. Methods are actions that allow for movement, sensing the presence of other objects, facilitating object-to-object interaction, and changing of group membership.

For example, a command to change the color of the first Bot in the Bots collection might look like this:

Bots(1).Color = vbtRed

The period (".") above serves to demark the different object hierarchies. Cycling through the Bots collection and changing the color of each Bot to red, might look like this:

For Each Bot In Bots
    Bot.Color = vbtRed
Next Bot

The same can be accomplished by manipulating the collection directly as in:

Bots.Color = vbtRed

There are over a 200 methods and properties in the VisualBots object model. The object model also includes functionality for simulation control, coordinate system definition, user-defined agent properties, math support, random number generation, and color management.

Why Excel?

VisualBots for Excel leverages the programming capabilities that exist in Excel, eliminating the need for a separate language interpreter. Simulations are written in Visual Basic using the Excel Visual Basic for Applications interface and saved with each Excel document. The VisualBots object model is complemented by the extensive spreadsheet functionality that already exists in Excel, such as data analysis and charting functions. The examples in our projects page of this web site make extensive use of the Excel Form controls for creating buttons, checkboxes, and edit boxes that work with the VisualBots simulator.

The Microsoft's Intellisense technology provides context-sensitive visual cues for coding with object methods, properties (left panel), and parameters (right panel). The programmer can browse the drop-down lists and select the appropriate item with the mouse.

Interested? Try it!

Visit our downloads web page to try the software yourself - its free.

You can view online the help documentation and sample projects that are included with the software.