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 nondeterministic, i. e., they return different values for each call.
Contents
Conventions[edit]
All functions and errors in this module are assigned to the http://basex.org/modules/random
namespace, which is statically bound to the random
prefix.
Functions[edit]
random:double[edit]
Signature | random:double() as xs:double |
Summary | Returns a double value between 0.0 (inclusive) and 1.0 (exclusive). |
random:integer[edit]
Signature | 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 | bounds : the maximum value is out of bounds.
|
random:seeded-double[edit]
Signature | 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 . |
random:seeded-integer[edit]
Signature | 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 | bounds : the maximum value is out of bounds.negative : the number of values to be returned is negative.
|
random:gaussian[edit]
Signature | 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. |
random:seeded-permutation[edit]
Signature | 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 . |
random:uuid[edit]
Signature | random:uuid() as xs:string |
Summary | Creates a random universally unique identifier (UUID), represented as 128-bit value. |
Examples |
|
Errors[edit]
Code | Description |
---|---|
bounds
|
The specified maximum value is out of bounds. |
negative
|
The specified number of values to be returned is negative. |
Changelog[edit]
- Version 9.0
- Updated: error codes updated; errors now use the module namespace
- Version 8.5
- Added:
random:seeded-permutation
- Version 8.0
- Updated:
random:integer
,random:seeded-integer
raise error for invalid input.
The module was introduced with Version 7.5. It includes some functionality which was previously located in the Math Module.