Re: [Fractint] Re: Mandelbrot and Julia Sets Explored by RareEvent Theory
Osher, Your posted reference to J. C, Sprotts work (Mandelbrot and Julia Sets Explored by Rare Event Theory, 29 Jan 2003) came along just as I was finding my way into related outcomes based on groups. The approach of using the order 4 cyclic group (C4) to generate the Mset in Fractint leads to a (WinXP friendly) formula such as Mset { x=real(pixel), y=imag(pixel), x1=y1=0: a=x1^2-y1^2+x b=2*x1*y1+y x1=a, y1=b z=sqrt(a^2+b^2) z < 10000 } I subsequently found a generalized formula that apparently works for groups of any order. In it, the Mset looks like this: C4e { x=real(pixel), y=imag(pixel), x1=x2=y1=y2=0: a1=x1^2+x2^2+2*y1*y2+x a2=2*x1*x2+y1^2+y2^2-x b1=2*x1*y1+2*x2*y2+y b2=2*x1*y2+2*x2*y1-y x1=a1, x2=a2, y1=b1, y2=b2 z=sqrt((a1-a2)^2+(b1-b2)^2) z < 10000 } But looking back at the first Mset formula, I saw it as a configuration of the pieces of the expansion of (a+b)^2. What would other arrangements lead to? For example: Mtest { x=real(pixel), y=imag(pixel)*p1, a=b=0: a1=a^2+a*b+x b1=b^2+a*b+y a=a1, b=b1 z=sqrt(a^2+b^2) z < 10000 } For p1=1, the result wasnt all that interesting, but for p1=(0,1), I got a bit of a surprise. That this too produces an Mset led to curiosity about other polynomial expansions, e.g., (a+b+c)^2 = a^2+b^2+c^2+2*a*b +2*a*c+2*b*c. I discovered that I could mix these up in about any arbitrary fashion and get a fractal object, and the more symmetry in the formula statements, the more to be found in the fractal itself. In the following example, p2 is meant to toggle between 1 and (0,1). Ptest {;use floating point x=real(pixel),y=imag(pixel)*p2,v=p1 a=b=c=0: a1=a^2-p2^2*a*b-p2^2*a*c b1=b^2-p2^2*a*b-p2^2*b*c c1=c^2-p2^2*c*b-p2^2*a*c a=a1+x,b=b1+y,c=c1+v z=sqrt(a^2+b^2+c^2) z < 10000} Where p2=1 produces a symmetrical object oriented toward the vertical, p2=i is an Mset again. Something I find interesting about Ptest is p1s effect on M. Plus/minus real p1 shift M left or right, imaginary p1 shift it up or down, and complex p1 at a corresponding angle. There seems to be zero distortion, as long as p1 isnt too close to the bailout value. Here are some examples of frm files created from (a+b+c)^3 Ptest2 { x=real(pixel),y=imag(pixel)*p2,v=p1 a=b=c=0: a1=a^3+3*b^2*a+3*c^2*a+2*a*b*c b1=b^3+3*a^2*b+3*c^2*b+2*a*b*c c1=c^3+3*a^2*c+3*b^2*c+2*a*b*c a=a1+x,b=b1+y,c=c1+v z=sqrt(a^2+b^2+c^2) z < 10000 } Ptest2 forms a square for p2=1,for p2=i an object similar to a third degree Mset (i.e., z1=z^3+c) and for p2=(1,1), a nice combination of the two. Ptest3 has an OK fractal in p2=i but nothing too exciting elsewhere that I discerned. Ptest3 { x=real(pixel),y=imag(pixel)*p2,v=p1 a=b=c=0: a1=a^3+b^3+c^3+6*x*y*z b1=3*b^2*c+3*c^2*a+3*a^2*b c1=3*c^2*b+3*a^2*c+3*b^2*a a=a1+x,b=b1+y,c=c1+v z=sqrt(a^2+b^2+c^2) z < 10000 } Thats a cursory look at it, but the idea of a class or classes of fractals based on polynomial expansions may prove eventually to harbor some interesting things... Ciao, Russ _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail
participants (1)
-
Russ Walsmith