WHAT IS A FRACTAL?

The shapes of rain cells as they are recorded by meteorological radar can appear chaotic, especially the contour lines drawn enclosing areas equal to or greater than a specified rain rate. However, further study shows that these contours have a statistically self-similar behaviour, which is consistent with fractal concepts. This therefore leads us to the study of rain fields using fractal methods. Figure 1: Contour lines enclosing areas equal to or greater than a specified rain rate. Fractals are most commonly known from TV and films, where they are either the subject of documentaries concerning chaotic systems and natural phenomena, or are used as part of the special effects to produce visually realistic, yet convincingly alien artificial landscapes. Some purely mathematical fractals, such as the Mandelbrot set, have achieved iconic status, and fractals in their pure mathematical form have been popularised with the users of home PCs through the spread and appeal of computer programs such as FRACTINT. James Gleick's book "Chaos " [Gleick, 1987] also helped to bring the appeal of fractals to a wider audience, making them popular with scientifically inclined members of the general public. The simplest way to describe a fractal is as an object that appears self-similar under varying degree