<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <link rel="stylesheet" href="style.css" type="text/css"> <meta content="text/html; charset=iso-8859-1" http-equiv="Content-Type"> <link rel="Start" href="index.html"> <link rel="previous" href="Queue.html"> <link rel="next" href="Ratio.html"> <link rel="Up" href="index.html"> <link title="Index of types" rel=Appendix href="index_types.html"> <link title="Index of exceptions" rel=Appendix href="index_exceptions.html"> <link title="Index of values" rel=Appendix href="index_values.html"> <link title="Index of modules" rel=Appendix href="index_modules.html"> <link title="Index of module types" rel=Appendix href="index_module_types.html"> <link title="Arg" rel="Chapter" href="Arg.html"> <link title="Arith_status" rel="Chapter" href="Arith_status.html"> <link title="Array" rel="Chapter" href="Array.html"> <link title="ArrayLabels" rel="Chapter" href="ArrayLabels.html"> <link title="Big_int" rel="Chapter" 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href="Tk.html"> <link title="Unix" rel="Chapter" href="Unix.html"> <link title="UnixLabels" rel="Chapter" href="UnixLabels.html"> <link title="Weak" rel="Chapter" href="Weak.html"><link title="Basic functions" rel="Section" href="#6_Basicfunctions"> <link title="Advanced functions" rel="Section" href="#6_Advancedfunctions"> <title>Random</title> </head> <body> <div class="navbar"><a class="pre" href="Queue.html" title="Queue">Previous</a> <a class="up" href="index.html" title="Index">Up</a> <a class="post" href="Ratio.html" title="Ratio">Next</a> </div> <h1>Module <a href="type_Random.html">Random</a></h1> <pre><span class="keyword">module</span> Random: <code class="code"><span class="keyword">sig</span></code> <a href="Random.html">..</a> <code class="code"><span class="keyword">end</span></code></pre><div class="info module top"> Pseudo-random number generators (PRNG).<br> </div> <hr width="100%"> <br> <h6 id="6_Basicfunctions">Basic functions</h6><br> <pre><span id="VALinit"><span class="keyword">val</span> init</span> : <code class="type">int -> unit</code></pre><div class="info "> Initialize the generator, using the argument as a seed. The same seed will always yield the same sequence of numbers.<br> </div> <pre><span id="VALfull_init"><span class="keyword">val</span> full_init</span> : <code class="type">int array -> unit</code></pre><div class="info "> Same as <a href="Random.html#VALinit"><code class="code"><span class="constructor">Random</span>.init</code></a> but takes more data as seed.<br> </div> <pre><span id="VALself_init"><span class="keyword">val</span> self_init</span> : <code class="type">unit -> unit</code></pre><div class="info "> Initialize the generator with a random seed chosen in a system-dependent way. If <code class="code">/dev/urandom</code> is available on the host machine, it is used to provide a highly random initial seed. Otherwise, a less random seed is computed from system parameters (current time, process IDs).<br> </div> <pre><span id="VALbits"><span class="keyword">val</span> bits</span> : <code class="type">unit -> int</code></pre><div class="info "> Return 30 random bits in a nonnegative integer.<br> <b>Before 3.12.0 </b> used a different algorithm (affects all the following functions)<br> </div> <pre><span id="VALint"><span class="keyword">val</span> int</span> : <code class="type">int -> int</code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.int bound</code> returns a random integer between 0 (inclusive) and <code class="code">bound</code> (exclusive). <code class="code">bound</code> must be greater than 0 and less than 2<sup class="superscript">30</sup>.<br> </div> <pre><span id="VALint32"><span class="keyword">val</span> int32</span> : <code class="type"><a href="Int32.html#TYPEt">Int32.t</a> -> <a href="Int32.html#TYPEt">Int32.t</a></code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.int32 bound</code> returns a random integer between 0 (inclusive) and <code class="code">bound</code> (exclusive). <code class="code">bound</code> must be greater than 0.<br> </div> <pre><span id="VALnativeint"><span class="keyword">val</span> nativeint</span> : <code class="type"><a href="Nativeint.html#TYPEt">Nativeint.t</a> -> <a href="Nativeint.html#TYPEt">Nativeint.t</a></code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.nativeint bound</code> returns a random integer between 0 (inclusive) and <code class="code">bound</code> (exclusive). <code class="code">bound</code> must be greater than 0.<br> </div> <pre><span id="VALint64"><span class="keyword">val</span> int64</span> : <code class="type"><a href="Int64.html#TYPEt">Int64.t</a> -> <a href="Int64.html#TYPEt">Int64.t</a></code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.int64 bound</code> returns a random integer between 0 (inclusive) and <code class="code">bound</code> (exclusive). <code class="code">bound</code> must be greater than 0.<br> </div> <pre><span id="VALfloat"><span class="keyword">val</span> float</span> : <code class="type">float -> float</code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.float bound</code> returns a random floating-point number between 0 and <code class="code">bound</code> (inclusive). If <code class="code">bound</code> is negative, the result is negative or zero. If <code class="code">bound</code> is 0, the result is 0.<br> </div> <pre><span id="VALbool"><span class="keyword">val</span> bool</span> : <code class="type">unit -> bool</code></pre><div class="info "> <code class="code"><span class="constructor">Random</span>.bool ()</code> returns <code class="code"><span class="keyword">true</span></code> or <code class="code"><span class="keyword">false</span></code> with probability 0.5 each.<br> </div> <br> <h6 id="6_Advancedfunctions">Advanced functions</h6><br> <br> The functions from module <code class="code"><span class="constructor">State</span></code> manipulate the current state of the random generator explicitly. This allows using one or several deterministic PRNGs, even in a multi-threaded program, without interference from other parts of the program.<br> <pre><span class="keyword">module</span> <a href="Random.State.html">State</a>: <code class="code"><span class="keyword">sig</span></code> <a href="Random.State.html">..</a> <code class="code"><span class="keyword">end</span></code></pre> <pre><span id="VALget_state"><span class="keyword">val</span> get_state</span> : <code class="type">unit -> <a href="Random.State.html#TYPEt">State.t</a></code></pre><div class="info "> Return the current state of the generator used by the basic functions.<br> </div> <pre><span id="VALset_state"><span class="keyword">val</span> set_state</span> : <code class="type"><a href="Random.State.html#TYPEt">State.t</a> -> unit</code></pre><div class="info "> Set the state of the generator used by the basic functions.<br> </div> </body></html>