Fractal type Formula.
In this case, the user defines all the equations and the parameters
for the calculation of the fractal (including the palet of colors).

4 functions can be used and 4 imaginary numbers.
The maximum number of lignes of code is 2,000.

A large number of functions are available :
sin(), cos(), tan(), cotan(), sinh(), cosh(), tanh(), cotanh(),
asin(), asinh(), acos(), acosh(), atan(), atanh(), exp(), log(),
sqr(), sqrt), recip(), flip(), ident(), conj(), cabs(), floor(),
ceil(), trunc(), real(), imag(), srand(), abs(), etc.

All the fractals named JMC-A99-xxx in this gallery are generated with 4 functions (fn1, fn2, fn3 and fn4)
and 3 imaginary numbers (p1, p2 and p3).
This equations cover many other groups of equations, including groups of equations provided by FRACTINT.

The equations used here are :

z = fn1(1/pixel)^real(p1), z1 = z;
z = fn2(z1)^real(p2) + fn3(z1)^imag(p2) + real(p3) / fn4(z1)^imag(p2);
|z| =< imag(p1)

For the factal here :
real(p1) = 4, imag(p1) = 2, real(p2) = 1, imag(p2) = 1, real(p3) = 1, imag(p3) = 1
fn1() = ident(), fn2 = cos(), fn3 = tanh(), fn4 = cotan().

Notes.
1) Many other parameters are used, but they are too complex to be explained here.
2) If a function is changed or if a parameter is modified (including a very small change,
like real(p1)=1 replaced by real(p1)=1.01, a drastic change of the fractal can be observed,
but often no fractal is drawn.