doc/parts/namespace/Shapes-Numeric-Random.sxml

   1 <?xml version="1.0" encoding="UTF-8"?>
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  19 <!-- Copyright 2015 Henrik Tidefelt                                         -->
  20
  21
  22 <book>
  23   <namespace>..Shapes..Numeric..Random</namespace>
  24   <description>
  25     <p>Random number generation.</p>
  26   </description>
  27
  28   <title><self /></title>
  29   <up-link><parent-namespace /></up-link>
  30   <base href=<!--#expand-next-string-->"$(BASE)" />
  31   <examples-home href=<!--#expand-next-string-->"$(EXAMPLES)" />
  32   <shapes-version number=<!--#expand-next-string-->"$(SHAPES_VERSION)" />
  33   <external>
  34     <!--#include virtual="^/toc.xml" -->
  35   </external>
  36
  37   <top>
  38     <alphabetical-index/>
  39     <p>Besides the most elementary things such as initializing the random state and then sampling uniformly from a huge range of integer values, <str-Shapes /> also comes with some more interesting distributions to sample from.  Distributions are not represented explicitly, only implicitly as the non-pure functions that return an object of some kind while acting on a random state.</p>
  40   </top>
  41
  42   <body>
  43
  44 <system-binding name="newRandom">
  45   <summary>Create random number generator seed</summary>
  46   <function>
  47     <top>
  48       <p>Create random number generator seed.</p>
  49     </top>
  50     <case>
  51       <arguments>
  52         <arg identifier="seed">
  53           <type>
  54             <union-type>
  55               <named-type name="Integer" />
  56               <named-type name="ChronologicalTime" />
  57             </union-type>
  58           </type>
  59         </arg>
  60         <arg identifier="size">
  61           <type><named-type name="Integer" /></type>
  62           <default><eq>32</eq></default>
  63         </arg>
  64       </arguments>
  65       <result>
  66         <type><named-type name="RandomSeed" /></type>
  67       </result>
  68       <dynamic-references></dynamic-references>
  69       <description>
  70         <p>Creates random number generator seed based on <arg name="seed" /> (agreed, <em>seed</em> being used with two slightly different meanings hre), with <arg name="size" /> number of bits.</p>
  71         <p>A random number generator seed is simply the initial state of a random number generator, but note that it is not possible to draw samples using the seed, since the seed is a value and not a state.  To draw samples, a <named-statetype name="Random" /> must be spawned from the seed.  Note that all <named-statetype name="Random" /> spawned from the same seed will generate the same pseudo random number sequence.</p>
  72       </description>
  73     </case>
  74   </function>
  75 </system-binding>
  76
  77 <system-state name="randomdevice">
  78   <type><named-statetype name="RandomDevice" /></type>
  79   <description>
  80     <p>Source of high quality random seeds.</p>
  81   </description>
  82 </system-state>
  83
  84   </body>
  85
  86 </book>