<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>urandom</title>
<link rel="stylesheet" type="text/css" href="csound.css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.76.1" />
<link rel="home" href="index.html" title="The Canonical Csound Reference Manual" />
<link rel="up" href="OpcodesTop.html" title="Orchestra Opcodes and Operators" />
<link rel="prev" href="upsamp.html" title="upsamp" />
<link rel="next" href="urd.html" title="urd" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">urandom</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="upsamp.html">Prev</a> </td>
<th width="60%" align="center">Orchestra Opcodes and Operators</th>
<td width="20%" align="right"> <a accesskey="n" href="urd.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry" title="urandom">
<a id="urandom"></a>
<div class="titlepage"></div>
<a id="IndexUrandom" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">urandom</span>
</h2>
<p>urandom —
truly random opcodes with controllable range.
</p>
</div>
<div class="refsect1" title="Description">
<a id="idp49880352"></a>
<h2>Description</h2>
<p>
truly random opcodes with controllable range. These
units are for Linux only and use /dev/urandom to construct
Csound random values
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="idp49881216"></a>
<h2>Syntax</h2>
<pre class="synopsis">ax <span class="command"><strong>urandom</strong></span> [imin, imax]</pre>
<pre class="synopsis">ix <span class="command"><strong>urandom</strong></span> [imin, imax]</pre>
<pre class="synopsis">kx <span class="command"><strong>urandom</strong></span> [imin, imax]</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="idp49910616"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>ix</em></span> -- i-rate output value.
</p>
<p>
<span class="emphasis"><em>imin</em></span> -- minimum value of range; defaults to -1.
</p>
<p>
<span class="emphasis"><em>imax</em></span> -- maximum value of range; defaults to +1.
</p>
<div class="note" title="Notes" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note: Notes">
<tr>
<td rowspan="2" align="center" valign="top" width="25">
<img alt="[Note]" src="images/note.png" />
</td>
<th align="left">Notes</th>
</tr>
<tr>
<td align="left" valign="top">
<p>
The algorithm produces 2^64 different possible values which
are scaled to fit the range requested. The randomness comes
form the usual Linux /dev/urandom method, and there is no
guarantee that it will be truly random, but there is a good
chance. It does not show any cycles.
</p>
</td>
</tr>
</table>
</div>
</div>
<div class="refsect1" title="Performance">
<a id="idp49913784"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ax</em></span> -- a-rate output value.
</p>
<p>
<span class="emphasis"><em>kx</em></span> -- k-rate output value.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="idp49915112"></a>
<h2>Examples</h2>
<p>
Here is an example of the urandom opcode at a-rate. It uses the file <a class="ulink" href="examples/urandom.csd" target="_top"><em class="citetitle">urandom.csd</em></a>.
</p>
<div class="example">
<a id="idp49916112"></a>
<p class="title">
<strong>Example 910. An example of the urandom opcode at a-rate.</strong>
</p>
<div class="example-contents">
<p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out Audio in</span>
-odac -iadc <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o rnd31.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="comment">; Initialize the global variables.</span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 1
<span class="comment">; Instrument #1.</span>
<span class="oblock">instr</span> 1
<span class="comment">; Create random numbers at a-rate in the range -2 to 2</span>
aur <span class="opc">urandom</span> <span class="op">-</span>2, 2
<span class="comment">; Use the random numbers to choose a frequency.</span>
afreq <span class="op">=</span> aur <span class="op">*</span> 500 <span class="op">+</span> 100
a1 <span class="opc">oscil</span> 30000, afreq, 1
<span class="opc">out</span> a1
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="comment">; Table #1, a sine wave.</span>
<span class="stamnt">f</span> 1 0 16384 10 1
<span class="comment">; Play Instrument #1 for one second.</span>
<span class="stamnt">i</span> 1 0 1
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
</p>
<p>
Here is an example of the urandom opcode at k-rate. It uses the file <a class="ulink" href="examples/urandom_krate.csd" target="_top"><em class="citetitle">urandom_krate.csd</em></a>.
</p>
<div class="example">
<a id="idp49919016"></a>
<p class="title">
<strong>Example 911. An example of the urandom opcode at k-rate.</strong>
</p>
<div class="example-contents">
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out Audio in</span>
-odac -iadc <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o rnd31_krate.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="comment">; Initialize the global variables.</span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 1
<span class="comment">; Instrument #1.</span>
<span class="oblock">instr</span> 1
<span class="comment">; Create random numbers at k-rate in the range -1 to 1 </span>
<span class="comment">; with a uniform distribution.</span>
k1 <span class="opc">urandom</span>
<span class="opc">printks</span> "k1<span class="op">=</span><span class="op">%</span>f\\n", 0.1, k1
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="comment">; Play Instrument #1 for one second.</span>
<span class="stamnt">i</span> 1 0 1
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
Its output should include lines like this:
</p>
<pre class="screen">
k1=0.229850
k1=-0.077047
k1=-0.199339
k1=-0.620577
k1=-0.119447
k1=-0.596258
k1=0.525800
k1=-0.171583
k1=-0.017196
k1=-0.974613
k1=-0.036276
</pre>
<p>
</p>
</div>
<div class="refsect1" title="Credits">
<a id="idp49920736"></a>
<h2>Credits</h2>
<p>Author: John ffitch</p>
<p>New in version 5.13</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="upsamp.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="OpcodesTop.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="urd.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">upsamp </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> urd</td>
</tr>
</table>
</div>
</body>
</html>
distrib
>
Mageia
>
5
>
x86_64
>
media
>
core-release
>
by-pkgid
>
b707d9a4ee443103660a75ccb6e51334
>
files
>
2784
