Mandelbrot fractal. Computer-generated image derived from a Mandelbrot Set. Fractal geometry is used to derive complex shapes as are often found in nature. The Mandelbrot Set, named after the mathematician Benoit B. Mandelbrot, is a group of complex numbers plotted using their real and imaginary parts as coordinates. Complex patterns are produced by a series of repeated mathematical operations or mappings. Generated on a computer screen, fractals are used to create models for real-world non-linear phenomena such as stock market prices, plant growth, the erosion of coastlines and fluid turbulence.