Use the mouse pointer to move the small, red square grid around. It represents a neighbourhood of a point in the complex plane. The twisted blue grid represents the image of the square grid.
The BLUE grid is the image of the RED grid for the selected function.
Currently there are three functions (thanks to improvements made by Djun Kim--there was originally only one function). With a little work, it could be made to evaluate more general expressions.
Keith Orpen