<?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>exprand</title> <link rel="stylesheet" type="text/css" href="csound.css" /> <link rel="stylesheet" type="text/css" href="syntax-highlighting.css" /> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /> <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="expon.html" title="expon" /> <link rel="next" href="exprandi.html" title="exprandi" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">exprand</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="expon.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="exprandi.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry"> <a id="exprand"></a> <div class="titlepage"></div> <a id="IndexExprandXClass" class="indexterm"></a> <a id="IndexExprand" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">exprand</span> </h2> <p>exprand — Exponential distribution random number generator (positive values only). </p> </div> <div class="refsect1"> <a id="idm281472938868536"></a> <h2>Description</h2> <p> Exponential distribution random number generator (positive values only). This is an x-class noise generator. </p> </div> <div class="refsect1"> <a id="idm281472938867384"></a> <h2>Syntax</h2> <pre class="synopsis">ares <span class="command"><strong>exprand</strong></span> klambda</pre> <pre class="synopsis">ires <span class="command"><strong>exprand</strong></span> klambda</pre> <pre class="synopsis">kres <span class="command"><strong>exprand</strong></span> klambda</pre> </div> <div class="refsect1"> <a id="idm281472938862872"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>klambda</em></span> -- lambda parameter for the exponential distribution. </p> <p> The probablity density function of an exponential distribution is an exponential curve, whose mean is 0.69515/lambda. For more detailed explanation of these distributions, see: </p> <div class="orderedlist"> <ol class="orderedlist" type="1"> <li class="listitem"> <p>C. Dodge - T.A. Jerse 1985. Computer music. Schirmer books. pp.265 - 286</p> </li> <li class="listitem"> <p>D. Lorrain. A panoply of stochastic cannons. In C. Roads, ed. 1989. Music machine . Cambridge, Massachusetts: MIT press, pp. 351 - 379.</p> </li> </ol> </div> <p> </p> </div> <div class="refsect1"> <a id="idm281472938858104"></a> <h2>Examples</h2> <p> Here is an example of the exprand opcode. It uses the file <a class="ulink" href="examples/exprand.csd" target="_top"><em class="citetitle">exprand.csd</em></a>. </p> <div class="example"> <a id="idm281472938856376"></a> <p class="title"> <strong>Example 255. Example of the exprand opcode.</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> <div class="refsect1"> <a id="idm281472770842248"></a> <pre class="programlisting"> <span class="nt"><CsoundSynthesizer></span> <span class="nt"><CsOptions></span> <span class="c1">; Select audio/midi flags here according to platform</span> -odac <span class="c1">;;;realtime audio out</span> <span class="c1">;-iadc ;;;uncomment -iadc if realtime audio input is needed too</span> <span class="c1">; For Non-realtime ouput leave only the line below:</span> <span class="c1">; -o exprand.wav -W ;;; for file output any platform</span> <span class="nt"></CsOptions></span> <span class="nt"><CsInstruments></span> <span class="vg">sr</span> <span class="o">=</span> <span class="mi">44100</span> <span class="vg">ksmps</span> <span class="o">=</span> <span class="mi">32</span> <span class="vg">nchnls</span> <span class="o">=</span> <span class="mi">2</span> <span class="vg">0dbfs</span> <span class="o">=</span> <span class="mi">1</span> <span class="kd">instr</span> <span class="nf">1</span> <span class="c1">; every run time same values</span> k<span class="n">lamda</span> <span class="nb">exprand</span> <span class="mi">20</span> <span class="nb">printk</span> <span class="mf">.2</span><span class="p">,</span> k<span class="n">lamda</span> <span class="c1">; look</span> a<span class="n">out</span> <span class="nb">oscili</span> <span class="mf">0.8</span><span class="p">,</span> <span class="mi">440</span><span class="o">+</span>k<span class="n">lamda</span><span class="p">,</span> <span class="mi">1</span> <span class="c1">; & listen</span> <span class="nb">outs</span> a<span class="n">out</span><span class="p">,</span> a<span class="n">out</span> <span class="kd">endin</span> <span class="kd">instr</span> <span class="nf">2</span> <span class="c1">; every run time different values</span> <span class="nb">seed</span> <span class="mi">0</span> k<span class="n">lamda</span> <span class="nb">exprand</span> <span class="mi">20</span> <span class="nb">printk</span> <span class="mf">.2</span><span class="p">,</span> k<span class="n">lamda</span> <span class="c1">; look </span> a<span class="n">out</span> <span class="nb">oscili</span> <span class="mf">0.8</span><span class="p">,</span> <span class="mi">440</span><span class="o">+</span>k<span class="n">lamda</span><span class="p">,</span> <span class="mi">1</span> <span class="c1">; & listen</span> <span class="nb">outs</span> a<span class="n">out</span><span class="p">,</span> a<span class="n">out</span> <span class="kd">endin</span> <span class="nt"></CsInstruments></span> <span class="nt"><CsScore></span> <span class="c1">; sine wave</span> <span class="nb">f</span> <span class="mi">1</span> <span class="mi">0</span> <span class="mi">16384</span> <span class="mi">10</span> <span class="mi">1</span> <span class="nb">i</span> <span class="mi">1</span> <span class="mi">0</span> <span class="mi">2</span> <span class="nb">i</span> <span class="mi">2</span> <span class="mi">3</span> <span class="mi">2</span> <span class="nb">e</span> <span class="nt"></CsScore></span> <span class="nt"></CsoundSynthesizer></span> </pre> </div> </div> </div> <p><br class="example-break" /> Its output should include lines like this: </p> <pre class="screen"> i 1 time 0.00033: 4.09813 i 1 time 0.20033: 56.39567 i 1 time 0.40033: 3.23362 i 1 time 0.60033: 0.24277 i 1 time 0.80033: 13.71228 i 1 time 1.00000: 12.71885 i 1 time 1.20033: 32.36737 i 1 time 1.40033: 0.29747 i 1 time 1.60033: 4.04450 i 1 time 1.80000: 35.75676 i 1 time 2.00000: 3.69845 Seeding from current time 3034472128 i 2 time 3.00033: 6.67934 i 2 time 3.20033: 2.72431 i 2 time 3.40033: 14.51822 i 2 time 3.60000: 12.10120 i 2 time 3.80033: 1.12266 i 2 time 4.00000: 26.90772 i 2 time 4.20000: 0.43554 i 2 time 4.40033: 28.59836 i 2 time 4.60033: 27.01831 i 2 time 4.80033: 18.19911 i 2 time 5.00000: 4.45125</pre> <p> </p> </div> <div class="refsect1"> <a id="idm281472938852168"></a> <h2>See Also</h2> <p> <a class="link" href="seed.html" title="seed"><em class="citetitle">seed</em></a>, <a class="link" href="betarand.html" title="betarand"><em class="citetitle">betarand</em></a>, <a class="link" href="bexprnd.html" title="bexprnd"><em class="citetitle">bexprnd</em></a>, <a class="link" href="cauchy.html" title="cauchy"><em class="citetitle">cauchy</em></a>, <a class="link" href="gauss.html" title="gauss"><em class="citetitle">gauss</em></a>, <a class="link" href="linrand.html" title="linrand"><em class="citetitle">linrand</em></a>, <a class="link" href="pcauchy.html" title="pcauchy"><em class="citetitle">pcauchy</em></a>, <a class="link" href="poisson.html" title="poisson"><em class="citetitle">poisson</em></a>, <a class="link" href="trirand.html" title="trirand"><em class="citetitle">trirand</em></a>, <a class="link" href="unirand.html" title="unirand"><em class="citetitle">unirand</em></a>, <a class="link" href="weibull.html" title="weibull"><em class="citetitle">weibull</em></a> </p> </div> <div class="refsect1"> <a id="idm281472938842744"></a> <h2>Credits</h2> <p> </p> <table border="0" summary="Simple list" class="simplelist"> <tr> <td>Author: Paris Smaragdis</td> </tr> <tr> <td>MIT, Cambridge</td> </tr> <tr> <td>1995</td> </tr> </table> <p> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="expon.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="exprandi.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">expon </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> exprandi</td> </tr> </table> </div> </body> </html>