Koch user's formula

[PBM]

Hi,

I've seen in source that for the Koch, it's:

zre1 = 1.5 * zre - 0.866 + 0.866 * zim;
zim1 = -1.5 + 1.5 * zim - 0.866 * zre;

What would be the user's formula in Xaos?

Thank you!

[Kovács Zoltán]

I am afraid that you will not be able to define a user formula for Koch, just because it is generated differently from the other classic fractals. The main difference is that the classic fractals define bailout with the absolute value of the current member of the sequence, but here another method is used (see the two lines below #define BTEST). The definition

    zre1 = 1.5 * zre - 0.866 + 0.866 * zim;
    zim1 = -1.5 + 1.5 * zim - 0.866 * zre;

    zre = zre1;
    zim = zim1;

actually means

z=(1.5 * Re(z) - 0.866 + 0.866 * Im(z)) + I*(-1.5 + 1.5 * Im(z) - 0.866 * Re(z))

but, because of the different bailout computation, you get something different.

Best, Zoltán