documentation about LAMBDA-fractals from fractint.exe (19.2)
This type calculates the Julia set of the formula lambda*Z*(1-Z). That
is, the value Z is initialized with the value corresponding to each
pixel position, and the formula iterated. The pixel is colored according
to the iteration when the sum of the squares of the real and imaginary
parts exceeds 4.
Two parameters, the real and imaginary parts of lambda, are required.
Try 0 and 1 to see the classical fractal "dragon". Then try 0.2 and 1
for a lot more detail to zoom in on.
It turns out that all quadratic Julia-type sets can be calculated using
just the formula z^2+c (the "classic" Julia"), so that this type is
redundant, but we include it for reason of it's prominence in the
history of fractals.