Vector fields model movement over an area or a volume. For example they can be used to describe the flow of air over an aeroplane wing, or past a car as it moves, and once these models have been set up they can be adjusted to produce an efficient, aerodynamic shape.

This article is simply based on the idea of addition of vectors in the plane and its aim is to produce effective displays of vector fields on the BBC microcomputer. Using animation techniques the vector fields are represented by a flow of dots on the screen. The program has been designed so that flows can be easily combined, making it possible to manipulate them as you wish to produce your own ‘aerodynamic’ two-dimensional car designs, ship-shapes, or bridge supports.