Random number generator

Random number generator

7.25.1 set_seed/1, randomize/0

Templates

: set_seed(+integer) randomize

Description

set_seed(Seed) reinitializes the random number generator seed with Seed.

randomize reinitializes the random number generator. This predicates calls set_seed/1 with a random value depending on the absolute time.

Errors

Seed is a variable instantiation_error

Seed is neither a variable nor an integer type_error(integer, Seed)

Seed is an integer < 0 domain_error(not_less_than_zero, Seed)

Portability

GNU Prolog predicates.

7.25.2 get_seed/1

Templates

: get_seed(?integer)

Description

get_seed(Seed) unifies Seed with the current random number generator seed.

Errors

Seed is neither a variable nor an integer type_error(integer, Seed)

Seed is an integer < 0 domain_error(not_less_than_zero, Seed)

Portability

GNU Prolog predicate.

7.25.3 random/1

Templates

: random(-float)

Description

random(Number) unifies Number with a random floating point number such that 0.0 <= Number < 1.0.

Errors

Number is not a variable type_error(variable, Number)

Portability

GNU Prolog predicate.

7.25.4 random/3

Templates

: random(+number, +number, -number)

Description

random(Base, Max, Number) unifies Number with a random number such that Base <= Number < Max. If both Base and Max are integers Number will be an integer, otherwise Number will be a floating point number.

Errors

Base is a variable instantiation_error

Base is neither a variable nor a number type_error(number, Base)

Max is a variable instantiation_error

Max is neither a variable nor a number type_error(number, Max)

Number is not a variable type_error(variable, Number)

Portability

GNU Prolog predicate.

Copyright (C) 1999-2002 Daniel Diaz.

Chapters 9 and 10 : Copyright (C) 2002-2003 INRIA, Rémy Haemmerlé.

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