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<div class="refentry" title="clear">
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<h2>
<span class="refentrytitle">clear</span>
</h2>
<p>clear —
Zeroes a list of audio signals.
</p>
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<div class="refsect1" title="Description">
<a id="idp15997504"></a>
<h2>Description</h2>
<p>
<span class="emphasis"><em>clear</em></span> zeroes a list of audio signals.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="idp15998352"></a>
<h2>Syntax</h2>
<pre class="synopsis"><span class="command"><strong>clear</strong></span> avar1 [, avar2] [, avar3] [...]</pre>
</div>
<div class="refsect1" title="Performance">
<a id="idp16008736"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>avar1, avar2, avar3,</em></span> ... -- signals to be zeroed
</p>
<p>
<span class="emphasis"><em>clear</em></span> sets every sample of each of the given audio signals to zero when it is performed. This is equivalent to writing <span class="emphasis"><em>avarN = 0</em></span> in the orchestra for each of the specified variables. Typically, <span class="emphasis"><em>clear</em></span> is used with global variables that combine multiple signals from different sources and change with each k-pass (performance loop) through all of the active instrument instances. After the final usage of such a variable and before the next k-pass, it is necessary to clear the variable so that it does not add the next cycle's signals to the previous result. <span class="emphasis"><em>clear</em></span> is especially useful in combination with <a class="link" href="vincr.html" title="vincr"><em class="citetitle">vincr</em></a> (variable increment) and they are intended to be used together with file output opcodes such as <a class="link" href="fout.html" title="fout"><em class="citetitle">fout</em></a>.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="idp16012248"></a>
<h2>Examples</h2>
<p>
Here is an example of the clear opcode. It uses the file <a class="ulink" href="examples/clear.csd" target="_top"><em class="citetitle">clear.csd</em></a>.
</p>
<div class="example">
<a id="idp16013216"></a>
<p class="title">
<strong>Example 109. Example of the clear opcode.</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>
-odac <span class="comment">;;;RT audio out</span>
<span class="comment">;-iadc ;;;uncomment -iadc if RT audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o clear.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
gaReverb <span class="opc">init</span> 0
<span class="oblock">instr</span> 1
idur <span class="op">=</span> p3
kpitch <span class="op">=</span> p4
a1 <span class="opc">diskin2</span> "fox.wav", kpitch
a1 <span class="op">=</span> a1<span class="op">*</span>.5 <span class="comment">;reduce volume</span>
<span class="opc">vincr</span> gaReverb, a1
<span class="oblock">endin</span>
<span class="oblock">instr</span> 99 <span class="comment">; global reverb </span>
al, ar <span class="opc">reverbsc</span> gaReverb, gaReverb, .8, 10000
<span class="opc">outs</span> gaReverb<span class="op">+</span>al, gaReverb<span class="op">+</span>ar
<span class="opc">clear</span> gaReverb
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="stamnt">i</span>1 0 3 1
<span class="stamnt">i</span>99 0 5
<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>
See the <a class="link" href="fout.html" title="fout"><em class="citetitle">fout</em></a> opcode for another example.
</p>
</div>
<div class="refsect1" title="See Also">
<a id="idp16046944"></a>
<h2>See Also</h2>
<p>
<a class="link" href="vincr.html" title="vincr"><em class="citetitle">vincr</em></a>
</p>
</div>
<div class="refsect1" title="Credits">
<a id="idp16048000"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Gabriel Maldonado</td>
</tr>
<tr>
<td>Italy</td>
</tr>
<tr>
<td>1999</td>
</tr>
</table>
<p>
</p>
<p>New in Csound version 3.56</p>
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distrib
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Mageia
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x86_64
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media
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core-release
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b707d9a4ee443103660a75ccb6e51334
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