Archive for the ‘Julia set’ tag
Happy New Year: drawing fractals in SQL
In one of my previous New Year's posts we drew snowflakes in PostgreSQL.
The algorithm we used to create the snowflakes is an implementation of an L-system, which is an example of a fractal. There are many more beautiful objects we can see in the winter: frozen trees, frost patterns on windows, cracks on ice etc., all of them being fractals.
Today we will be constructing escape-time fractals. To build such a fractal, one would need to run a certain function for each point on the plane iteratively and see how many iterations does it take for the function to overflow: the more it takes, the brighter is the point's color.
I won't go deep into fractal theory now, just show that they can be constructed with SQL relatively easily. For instance, Mandelbrot set, one of the best known escape-time fractals, is almost a one-liner in PostgreSQL: