Knot
x=-y;
y=x*x*x-x-y;
Insect
x=y;
y=y*y+x+y;
Eshape
x=-y;
y=x+y+1/y;
Square
x=-0.999776*y;
y=x;
Triangle
x=-0.999776*y;
y=x-y;
Hexagon
x=-0.999776*y;
y=x+y;
Square/Circle
x=-0.999776*y;
y=x+0.1*y;
4 spirals
x=.004*x+y;
y=(-1./y - y)/x;
Pentagon
x=x*0.6 -y;
y=0.1*x*y +x;
Diagonal
x=.001*y+y;
y=x;
Circle of circles
x=y;
y=-0.288/y +0.5*y - x;
Chaotic oval
x = x/y -x;
y = x*x - 0.24;
Chaotic shell
x = x*y + 0.357057*x -y;
y = x + y;