Readme {
;This .FRM file by Mike Wareman.
;Secant method general formula:
;z[k+1] = z[k] - f(z[k]) * (z[k] - z[k-1]) / (f(z[k]) - f(z[k-1])
;In the formula I used p1 so that you can change the initial value
;of z0 which results in different pictures.  Also, you will need to
;set the floating point parameter to YES.
;REFERENCE:
;Szyszkowicz, Mieczyslaw.  "Computer art generated by the method of secants
;in the complex plane."  COMPUTERS AND GRAPHICS,  volume 14, number 3/4, p.
;509.
}

Secant_z4-1 {
;The Fractint formula for z^4-1 is:
z = pixel,
z0 = p1:
zt = z;
z1 = z0 * z0 * z0 * z0 - 1;
z2 = z * z * z * z - 1;
z = z - z2 * (z - z0) / (z2 - z1);
z0 = zt;
|z2| > 0.001
}