Random values

Some formulas need to calculate random values. Ultra Fractal offers two ways of obtaining pseudo 

random values.

The predefined symbol 

#random

 returns a new complex random number for every pixel. This exists 

primarily for compatibility with old Fractint formulas.

The preferred way of obtaining a random value is the 

random

 function. This function accepts an 

integer seed and returns a new random seed. To generate a series of random numbers, you should 

call the function repeatedly, each time supplying the seed returned by the previous call. Example:

int 

seed = 

123456789 

; initial value

seed = 

random

(seed)

; seed is now the first random number

seed = 

random

(seed)

; seed is now the second random number

To obtain a random floating point number between 0 and 1, divide abs(seed) by the predefined 

symbol 

#randomrange

. To obtain a random integer between 0 and n   1, use abs(seed) % n.

You can generate multiple independent, reproducible series of random numbers just by declaring and 

using multiple seeds. The random function will always return the same result for the same seed 

value.

Next: 

Symmetry

See Also

Global sections

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