Test data base

To test these tools, I use data generated by dynamical systems. The test data is produced by iterating formulas like those which follow, starting from a given point in the plane. By changing the starting point you can generate a different set of numbers.

These can be easily put in graphical form.

The formulas themselves are found by a computer program trying random formulas and keeping those that give an image(attractor) in a given window.

A database of around 50,000 discrete planar dynamical systems, has thus been created. Here is a small subsample of 12 of them:

x=-y;                 x=y;                      x=-y;
y=x*x*x-x-y;          y=y*y+x+y;                y=x+y+1/y;

x=-0.999776*y;        x=-0.999776*y;            x=-0.999776*y;
y=x;                  y=x-y;                    y=x+y;

x=-0.999776*y;        x=.004*x+y;               x=x*0.6 -y;
y=x+0.1*y;            y=(-1./y - y)/x;          y=0.1*x*y +x;

x=.001*y+y;           x=y;                      x = x/y -x;
y=x;                  y=-0.288/y +0.5*y - x;    y = x*x - 0.24;