<?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>polynomial</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="polyaft.html" title="polyaft" /> <link rel="next" href="pop.html" title="pop" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">polynomial</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="polyaft.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="pop.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry" title="polynomial"> <a id="polynomial"></a> <div class="titlepage"></div> <a id="IndexPolynomial" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">polynomial</span> </h2> <p>polynomial — Efficiently evaluates a polynomial of arbitrary order. </p> </div> <div class="refsect1" title="Description"> <a id="idp36719016"></a> <h2>Description</h2> <p> The <span class="emphasis"><em>polynomial</em></span> opcode calculates a polynomial with a single a-rate input variable. The polynomial is a sum of any number of terms in the form <span class="emphasis"><em>kn*x^n</em></span> where <span class="emphasis"><em>kn</em></span> is the nth coefficient of the expression. These coefficients are k-rate values. </p> </div> <div class="refsect1" title="Syntax"> <a id="idp36720464"></a> <h2>Syntax</h2> <pre class="synopsis">aout <span class="command"><strong>polynomial</strong></span> ain, k0 [, k1 [, k2 [...]]]</pre> </div> <div class="refsect1" title="Performance"> <a id="idp36721576"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>ain</em></span> -- the input signal used as the independent variable of the polynomial ("x"). </p> <p> <span class="emphasis"><em>aout</em></span> -- the output signal ("y"). </p> <p> <span class="emphasis"><em>k0, k1, k2, ...</em></span> -- the coefficients for each term of the polynomial. </p> <p> If we consider the input parameter <span class="emphasis"><em>ain</em></span> to be "x" and the output <span class="emphasis"><em>aout</em></span> to be "y", then the <span class="emphasis"><em>polynomial</em></span> opcode calculates the following equation: </p> <div class="literallayout"> <p><br /> y = k0 + k1*x + k2*x^2 + k3*x^3 + ...<br /> </p> </div> <p> </p> </div> <div class="refsect1" title="Examples"> <a id="idp36724872"></a> <h2>Examples</h2> <p> Here is an example of the polynomial opcode. It uses the file <a class="ulink" href="examples/polynomial.csd" target="_top"><em class="citetitle">polynomial.csd</em></a>. </p> <div class="example"> <a id="idp36725864"></a> <p class="title"> <strong>Example 602. Example of the polynomial 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> <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> -odac <span class="comment">;;;realtime audio</span> <span class="comment">;-iadc ;;;uncomment -iadc if realtime audio input is needed too</span> <span class="comment">; For Non-realtime ouput leave only the line below:</span> <span class="comment">; -o polynomial.wav -W ;;; for file output any platform</span> <span class="csdtag"></CsOptions></span> <span class="csdtag"><CsInstruments></span> <span class="ohdr">sr</span> <span class="op">=</span> 44100 <span class="ohdr">ksmps</span> <span class="op">=</span> 32 <span class="ohdr">nchnls</span> <span class="op">=</span> 2 <span class="ohdr">0dbfs</span> <span class="op">=</span> 1 <span class="comment">; The polynomial y=x^n where n is odd always produces a curve</span> <span class="comment">; that traverses the range [-1, 1] when the input is within</span> <span class="comment">; the same range. Therefore, we can use one of these curves</span> <span class="comment">; to make a nonlinear phasor that repeatedly reads a table </span> <span class="comment">; from beginning to end like a linear phasor (maintaining </span> <span class="comment">; continuity) but that distorts the waveform in the table.</span> <span class="oblock">instr</span> 4 <span class="comment">; This instrument demonstrates phase distortion with x^3</span> idur <span class="op">=</span> p3 iamp <span class="op">=</span> p4 ifreq <span class="op">=</span> p5 itable <span class="op">=</span> p6 aenv <span class="opc">linseg</span> 0, .001, 1.0, idur <span class="op">-</span> .051, 1.0, .05, 0 <span class="comment">; declicking envelope</span> aosc <span class="opc">phasor</span> ifreq <span class="comment">; create a linear phasor</span> apd <span class="opc">polynomial</span> aosc, 0, 0, 0, 1 <span class="comment">; distort the phasor with x^3</span> aout <span class="opc">tablei</span> apd, itable, 1 <span class="comment">; read a sine table with the nonlinear phasor</span> <span class="opc">outs</span> aenv<span class="op">*</span>aout<span class="op">*</span>iamp, aenv<span class="op">*</span>aout<span class="op">*</span>iamp <span class="oblock">endin</span> <span class="oblock">instr</span> 5 <span class="comment">; This instrument demonstrates phase distortion with x^11</span> idur <span class="op">=</span> p3 iamp <span class="op">=</span> p4 ifreq <span class="op">=</span> p5 itable <span class="op">=</span> p6 aenv <span class="opc">linseg</span> 0, .001, 1.0, idur <span class="op">-</span> .051, 1.0, .05, 0 <span class="comment">; declicking envelope</span> aosc <span class="opc">phasor</span> ifreq <span class="comment">; create a linear phasor</span> apd <span class="opc">polynomial</span> aosc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 <span class="comment">; distort the phasor with x^11</span> aout <span class="opc">tablei</span> apd, itable, 1 <span class="comment">; read a sine table with the nonlinear phasor</span> <span class="opc">outs</span> aenv<span class="op">*</span>aout<span class="op">*</span>iamp, aenv<span class="op">*</span>aout<span class="op">*</span>iamp <span class="oblock">endin</span> <span class="oblock">instr</span> 6 <span class="comment">; This instrument crossfades between a pure sine and one distorted with x^11</span> idur <span class="op">=</span> p3 iamp <span class="op">=</span> p4 ifreq <span class="op">=</span> p5 itable <span class="op">=</span> p6 aenv <span class="opc">linseg</span> 0, .001, 1.0, idur <span class="op">-</span> .051, 1.0, .05, 0 <span class="comment">; declicking envelope</span> aosc <span class="opc">phasor</span> ifreq <span class="comment">; create a linear phasor</span> aout3 <span class="opc">tablei</span> aosc, itable, 1 <span class="comment">; read a sine table without the linear phasor</span> apd11 <span class="opc">polynomial</span> aosc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 <span class="comment">; distort the phasor with x^11</span> aout11 <span class="opc">tablei</span> apd11, itable, 1 <span class="comment">; read a sine table with the nonlinear phasor</span> kamount <span class="opc">linseg</span> 1.0, 0.05, 0.9, 1.0, 0.0 <span class="comment">; crossfade between two outputs</span> aout <span class="op">=</span> aout3<span class="op">*</span>kamount <span class="op">+</span> aout11<span class="op">*</span>(1.0 <span class="op">-</span> kamount) <span class="opc">outs</span> aenv<span class="op">*</span>aout<span class="op">*</span>iamp, aenv<span class="op">*</span>aout<span class="op">*</span>iamp <span class="oblock">endin</span> <span class="csdtag"></CsInstruments></span> <span class="csdtag"><CsScore></span> <span class="stamnt">f</span>1 0 16385 10 1 <span class="comment">; sine wave</span> <span class="comment">; descending "just blues" scale</span> <span class="stamnt">t</span> 0 100 <span class="stamnt">i</span>4 0 .333 .7 512 1 <span class="stamnt">i</span>. + . . 448 <span class="stamnt">i</span>. + . . 384 <span class="stamnt">i</span>. + . . 360 <span class="stamnt">i</span>. + . . 341.33 <span class="stamnt">i</span>. + . . 298.67 <span class="stamnt">i</span>. + 2 . 256 <span class="stamnt">s</span> <span class="stamnt">t</span> 0 100 <span class="stamnt">i</span>5 0 .333 .7 512 1 <span class="stamnt">i</span>. + . . 448 <span class="stamnt">i</span>. + . . 384 <span class="stamnt">i</span>. + . . 360 <span class="stamnt">i</span>. + . . 341.33 <span class="stamnt">i</span>. + . . 298.67 <span class="stamnt">i</span>. + 2 . 256 <span class="stamnt">s</span> <span class="stamnt">t</span> 0 100 <span class="stamnt">i</span>6 0 .333 .7 512 1 <span class="stamnt">i</span>. + . . 448 <span class="stamnt">i</span>. + . . 384 <span class="stamnt">i</span>. + . . 360 <span class="stamnt">i</span>. + . . 341.33 <span class="stamnt">i</span>. + . . 298.67 <span class="stamnt">i</span>. + 2 . 256 <span class="stamnt">e</span> <span class="csdtag"></CsScore></span> <span class="csdtag"></CsoundSynthesizer></span> </pre> </div> </div> <p><br class="example-break" /> </p> </div> <div class="refsect1" title="See Also"> <a id="idp36728144"></a> <h2>See Also</h2> <p> <a class="link" href="chebyshevpoly.html" title="chebyshevpoly"><em class="citetitle">chebyshevpoly</em></a>, <a class="link" href="mac.html" title="mac"><em class="citetitle">mac</em></a> <a class="link" href="maca.html" title="maca"><em class="citetitle">maca</em></a> </p> </div> <div class="refsect1" title="Credits"> <a id="idp36730096"></a> <h2>Credits</h2> <p> </p> <table border="0" summary="Simple list" class="simplelist"> <tr> <td>Author: Anthony Kozar</td> </tr> <tr> <td>January 2008</td> </tr> </table> <p> </p> <p>New in Csound version 5.08</p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="polyaft.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="pop.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">polyaft </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> pop</td> </tr> </table> </div> </body> </html>