WeaverBird Overview

Computer models are used in research, in design, in teaching and in business. They can be used whenever you want to make a simplified representation of a real, future, or imaginary system. They can be used to describe a system and/or analyse it. But they have a problem; they are often hard to use, and almost always hard to develop.

WeaverBird is a single user modelling program that runs on a PC that was designed to solve these problems of ease of use. It has five striking features, the first two of which are commonly implemented in good modelling programs, and the last three are almost unique.

Data-centric not Drawing-centric

In WeaverBird, diagrams, and maybe some text, are generated from the data. When a model designer defines a diagram, they don’t draw it, but instead they define the rules for converting model data into diagram drawing instructions. This has many advantages. As the data changes so do the diagrams, without any redrawing effort. You can make the diagrams respond to mouse clicks, for instance to expand some part of the diagram, contract part of the diagram, display explanatory text, change the size or position of a shape. The same underlying data can be represented in two or more kinds of diagram and there are no concerns about ensuring consistency between them. Furthermore it is straightforward to write code to analyse structured data whereas analysing drawing instructions is in practice unrealistic.

Dynamic Diagrams

Shapes can be put into motion which immediately makes them the centre of attention. Or you can make a line or other shape, gradually grow or shrink. This is ideal for showing dynamic behaviour like data flowing through an IT application or mechanical parts moving.

Active Text Front End

You can create an active text front end for a model. Active text is text with links like web pages. The links can take you to other parts of document, to external web pages or a generated diagram display.

A frequent problem with modelling programs is that all users – management and business users as well as technical staff – need some training. An active text front end in a WeaverBird model eliminates this need for model readers. You can therefore create a model and send it to many people, with the expectation that they can look at the model and look at your diagrams, and be guided through what the model means by the text without having had any training in either WeaverBird or your model.

Generic Modelling

There are many modelling programs, for instance, spreadsheet programs for financial models, IT design tools for UML models, CAD programs for models of mechanical objects, and weather models for forecasting or climate prediction. WeaverBird is generic. The model designer defines the structure of the data and writes the routines for converting the model data into diagrams.

Spreadsheet programs do provide a generic modelling capability. WeaverBird differs from spreadsheet programs in having structured data (rather like a database) not a tabular sheet, and being able to generate any kind of diagram not only charts.

Single File like an Office Product

The model is encapsulated in a single file that holds not only the model data but the logic for generating diagrams and the report text. This means it can be sent by email, downloaded from a web site or put on a CD. The model file can be read by a free program that can be downloaded from the download page.

When to Use WeaverBird

WeaverBird is not a competitor to specialised modelling products. What it is, is an alternative way of communicating information. It is an alternative to things like to white papers, reference documents, tutorials and even electronic marketing brochures.

Some examples of using WeaverBird are found in the example found on the models page.

In general you should think about using a WeaverBird model in preference to another kind of office program when:

• You need to explain complexity. The dynamic diagramming facilities, especially moving or changing shapes, is ideal for explaining complex system that have many interacting parts. Furthermore the diagrams are generated from the data which means that you can have a host of examples, all consistently using the same diagrammatic conventions, and that you can select an element in one diagram to become the focus of a new diagram. In practice, it means the user can explore the information rather than be rail-roaded through a passive presentation of the information.
• Keep data, diagrams and text in sync. It is possible not only to generate diagrams from the model data, but also to generated text from the model data. Thus WeaverBird is ideal for building visual directories, or design documents.
• Analyse the model data. WeaverBird has a powerful in-built language for processing and analysing data, and you can provide the reader with parameterized analysis routines. The output from an analysis routine may be a diagram instead of or as well as data. The diagrams can be conventional bar charts, graphs, etc, but you have the full diagramming facilitities available, so you may want, for instance, to overlay your bar charts on an image or on diagram shapes.