object

random

Portable random number generator predicates. Core predicates originally written by Richard O’Keefe. Based on algorithm AS 183 from Applied Statistics.

Availability:
logtalk_load(random(loader))
Author: Paulo Moura
Version: 2:11:0
Date: 2023-11-24
Compilation flags:
static, context_switching_calls
Implements:
public pseudo_random_protocol
Uses:
list
Remarks:

  • Multiple random number generators: To define multiple random number generators, simply extend this object. The derived objects must send to self the reset_seed/0 message.

  • Randomness: Loading this object always initializes the random generator seed to the same value, thus providing a pseudo random number generator. The randomize/1 predicate can be used to initialize the seed with a random value.

Inherited public predicates:
 between/3  enumerate/2  get_seed/1  maybe/0  maybe/1  maybe/2  maybe_call/1  maybe_call/2  member/2  permutation/2  random/1  random/3  randseq/4  randset/4  select/3  select/4  sequence/4  set/4  set_seed/1  swap/2  swap_consecutive/2

Public predicates

reset_seed/0

Resets the random generator seed to its default value. Use get_seed/1 and set_seed/1 instead if you need reproducibility.

Compilation flags:
static, synchronized
Mode and number of proofs:
reset_seed - one

randomize/1

Randomizes the random generator using a positive integer to compute a new seed. Use of a large integer is recommended. In alternative, when using a small integer argument, discard the first dozen random values.

Compilation flags:
static, synchronized
Template:
randomize(Seed)
Mode and number of proofs:
randomize(+positive_integer) - one

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

seed_/3

Stores the current random generator seed values.

Compilation flags:
dynamic
Template:
seed_(S0,S1,S2)
Mode and number of proofs:
seed_(-integer,-integer,-integer) - one

Operators

(none)

See also

fast_random, backend_random