## table of contents

- buster 4.05.0-11

Random(3o) | OCamldoc | Random(3o) |

# NAME¶

Random - Pseudo-random number generators (PRNG).# Module¶

Module Random# Documentation¶

Module**Random**:

**sig end**

Pseudo-random number generators (PRNG).

**===** **Basic functions** **===**

*val init* : **int -> unit**

Initialize the generator, using the argument as a seed. The same seed will always yield the same sequence of numbers.

*val full_init* : **int array -> unit**

Same as **Random.init** but takes more data as seed.

*val self_init* : **unit -> unit**

Initialize the generator with a random seed chosen in a
system-dependent way. If **/dev/urandom** is available on the host
machine, it is used to provide a highly random initial seed. Otherwise, a
less random seed is computed from system parameters (current time, process
IDs).

*val bits* : **unit -> int**

Return 30 random bits in a nonnegative integer.

**Before3.12.0** used a different algorithm (affects all the
following functions)

*val int* : **int -> int**

**Random.int bound** returns a random integer between 0
(inclusive) and **bound** (exclusive). **bound** must be greater than
0 and less than 2^{30.

*val int32* : **Int32.t -> Int32.t**

**Random.int32 bound** returns a random integer between 0
(inclusive) and **bound** (exclusive). **bound** must be greater than
0.

*val nativeint* : **Nativeint.t -> Nativeint.t**

**Random.nativeint bound** returns a random integer between 0
(inclusive) and **bound** (exclusive). **bound** must be greater than
0.

*val int64* : **Int64.t -> Int64.t**

**Random.int64 bound** returns a random integer between 0
(inclusive) and **bound** (exclusive). **bound** must be greater than
0.

*val float* : **float -> float**

**Random.float bound** returns a random floating-point number
between 0 and **bound** (inclusive). If **bound** is negative, the
result is negative or zero. If **bound** is 0, the result is 0.

*val bool* : **unit -> bool**

**Random.bool ()** returns **true** or **false** with
probability 0.5 each.

**===** **Advanced functions** **===**

**=== The functions from module Random.State manipulate the
current state** **of the random generator explicitly.** **This allows
using one or several deterministic PRNGs,** **even in a multi-threaded
program, without interference from** **other parts of the program.
===**

*module State :* **sig end**

*val get_state* : **unit -> State.t**

Return the current state of the generator used by the basic functions.

*val set_state* : **State.t -> unit**

Set the state of the generator used by the basic functions.

source: | 2019-01-25 |