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<h2>
<span class="refentrytitle">GEN19</span>
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<p>GEN19 —
Generate composite waveforms made up of weighted sums of simple sinusoids.
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<div class="refsect1" title="Description">
<a id="id3738558"></a>
<h2>Description</h2>
<p>
These subroutines generate composite waveforms made up of weighted sums of simple sinusoids. The specification of each contributing partial requires 4 p-fields using <span class="emphasis"><em>GEN19</em></span>.
</p>
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<div class="refsect1" title="Syntax">
<a id="id3738575"></a>
<h2>Syntax</h2>
<pre class="synopsis"><span class="command"><strong>f</strong></span> # time size 19 pna stra phsa dcoa pnb strb phsb dcob ...</pre>
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<div class="refsect1" title="Initialization">
<a id="id3739430"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>size</em></span> -- number of points in the table. Must be a power of 2 or power-of-2 plus 1 (see <a class="link" href="f.html" title="f Statement (or Function Table Statement)"><em class="citetitle">f statement</em></a>).
</p>
<p>
<span class="emphasis"><em>pna, pnb</em></span>, etc. -- partial no. (relative to a fundamental that would occupy <span class="emphasis"><em>size</em></span> locations per cycle) of sinusoid a, sinusoid b, etc. Must be positive, but need not be a whole number, i.e., non-harmonic partials are permitted. Partials may be in any order.
</p>
<p>
<span class="emphasis"><em>stra, strb</em></span>, etc. -- strength of partials <span class="emphasis"><em>pna, pnb</em></span>, etc. These are relative strengths, since the composite waveform may be rescaled later. Negative values are permitted and imply a 180 degree phase shift.
</p>
<p>
<span class="emphasis"><em>phsa, phsb</em></span>, etc. -- initial phase of partials <span class="emphasis"><em>pna, pnb,</em></span> etc., expressed in degrees.
</p>
<p>
<span class="emphasis"><em>dcoa, dcob</em></span>, etc. -- DC offset of partials <span class="emphasis"><em>pna, pnb</em></span>, etc. This is applied <span class="emphasis"><em>after</em></span> strength scaling, i.e. a value of 2 will lift a 2-strength sinusoid from range [-2,2] to range [0,4] (before later rescaling).
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<p>
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<div class="itemizedlist">
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<p>
These subroutines generate stored functions as sums of sinusoids of different frequencies. The two major restrictions on <span class="emphasis"><em>GEN10</em></span> that the partials be harmonic and in phase do not apply to <span class="emphasis"><em>GEN09</em></span> or <span class="emphasis"><em>GEN19</em></span>.
</p>
<p>
In each case the composite wave, once drawn, is then rescaled to unity if p4 was positive. A negative p4 will cause rescaling to be skipped.
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<div class="refsect1" title="Examples">
<a id="id3739563"></a>
<h2>Examples</h2>
<p>
Here is a simple example of the GEN19 routine. It uses the file <a class="ulink" href="examples/gen19.csd" target="_top"><em class="citetitle">gen19.csd</em></a>. It will generate a nice bell curve, here is its diagram:
</p>
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<img src="images/gen19.png" alt="Diagram of the waveform generated by GEN19." />
<div class="caption">
<p>Diagram of the waveform generated by GEN19.</p>
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<p>
</p>
<div class="example">
<a id="id3739609"></a>
<p class="title">
<b>Example 748. A simple example of the GEN19 routine.</b>
</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 gen19.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 an index over the length of our entire note.</span>
kcps <span class="opc">init</span> 1<span class="op">/</span>p3
kndx <span class="opc">phasor</span> kcps
<span class="comment">; Read Table #1 with our index.</span>
ifn <span class="op">=</span> 1
ixmode <span class="op">=</span> 1
kval <span class="opc">table</span> kndx, ifn, ixmode
<span class="comment">; Generate a sine waveform, use our Table #1 value to </span>
<span class="comment">; vary its frequency by 100 Hz from its base frequency.</span>
ibasefreq <span class="op">=</span> 440
kfreq <span class="op">=</span> kval <span class="op">*</span> 100
a1 <span class="opc">oscil</span> 20000, ibasefreq <span class="op">+</span> kfreq, 2
<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 bell curve (using GEN19).</span>
<span class="stamnt">f</span> 1 0 16384 -19 1 1 260 1
<span class="comment">; Table #2, a sine wave.</span>
<span class="stamnt">f</span> 2 0 16384 10 1
<span class="comment">; Play Instrument #1 for 3 seconds.</span>
<span class="stamnt">i</span> 1 0 3
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
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<p><br class="example-break" />
</p>
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<div class="refsect1" title="See Also">
<a id="id3739649"></a>
<h2>See Also</h2>
<p>
<a class="link" href="GEN09.html" title="GEN09"><em class="citetitle">GEN09</em></a> and
<a class="link" href="GEN10.html" title="GEN10"><em class="citetitle">GEN10</em></a>
</p>
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<div class="refsect1" title="Credits">
<a id="id3739674"></a>
<h2>Credits</h2>
<p>Example written by Kevin Conder</p>
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