Random Module

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This XQuery Module contains functions for computing random values. All functions except for random:seeded-double and random:seeded-integer are non-deterministic, i. e., they return different values for each call.

Contents

[edit] Conventions

All functions in this module are assigned to the http://basex.org/modules/random namespace, which is statically bound to the random prefix.
All errors are assigned to the http://basex.org/errors namespace, which is statically bound to the bxerr prefix.

[edit] Functions

[edit] random:double

Signatures random:double() as xs:double
Summary Returns a double value between 0.0 (inclusive) and 1.0 (exclusive).

[edit] random:integer

Signatures random:integer() as xs:integer
random:integer($max as xs:integer) as xs:integer
Summary Returns an integer value, either in the whole integer range or between 0 (inclusive) and the given maximum (exclusive)
Errors BXRA0001: the maximum value is out of bounds.

[edit] random:seeded-double

Signatures random:seeded-double($seed as xs:integer, $num as xs:integer) as xs:double*
Summary Returns a sequence with $num double values between 0.0 (inclusive) and 1.0 (exclusive). The random values are created using the initial seed given in $seed.

[edit] random:seeded-integer

Signatures random:seeded-integer($seed as xs:integer, $num as xs:integer) as xs:integer*
random:seeded-integer($seed as xs:integer, $num as xs:integer, $max as xs:integer) as xs:integer*
Summary Returns a sequence with $num integer values, either in the whole integer range or between 0 (inclusive) and the given maximum (exclusive). The random values are created using the initial seed given in $seed.
Errors BXRA0001: the maximum value is out of bounds.
BXRA0002: the number of values to be returned is negative.

[edit] random:gaussian

Signatures random:gaussian($num as xs:integer) as xs:double*
Summary Returns a sequence with $num double values. The random values are Gaussian (i.e. normally) distributed with the mean 0.0. and the derivation 1.0.

[edit] random:seeded-permutation

Introduced with Version 8.5:

Signatures random:seeded-permutation($seed as xs:integer, $items as item()*) as item()*
Summary Returns a random permutation of the specified $items. The random order is created using the initial seed given in $seed.

[edit] random:uuid

Signatures random:uuid() as xs:string
Summary Creates a random universally unique identifier (UUID), represented as 128-bit value.
Examples
  • random:uuid() eq random:uuid() will (most probably) return the boolean value false.

[edit] Errors

Code Description
BXRA0001 The specified maximum value is out of bounds.
BXRA0002 The specified number of values to be returned is negative.

[edit] Changelog

Version 8.5
Version 8.0

The module was introduced with Version 7.5. It includes some functionality which was previously located in the Math Module.

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