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&#160;<span id="projectnumber">Version 1.5.1</span>
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<a href="#func-members">Functions</a> </div>
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<div class="title">Cosine<div class="ingroups"><a class="el" href="group__groupFastMath.html">Fast Math Functions</a></div></div> </div>
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<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:gace15287f9c64b9b4084d1c797d4c49d8"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__cos.html#gace15287f9c64b9b4084d1c797d4c49d8">arm_cos_f32</a> (<a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a> x)</td></tr>
<tr class="memdesc:gace15287f9c64b9b4084d1c797d4c49d8"><td class="mdescLeft">&#160;</td><td class="mdescRight">Fast approximation to the trigonometric cosine function for floating-point data. <a href="#gace15287f9c64b9b4084d1c797d4c49d8">More...</a><br/></td></tr>
<tr class="separator:gace15287f9c64b9b4084d1c797d4c49d8"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:gadfd60c24def501638c0d5db20f4c869b"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__cos.html#gadfd60c24def501638c0d5db20f4c869b">arm_cos_q15</a> (<a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> x)</td></tr>
<tr class="memdesc:gadfd60c24def501638c0d5db20f4c869b"><td class="mdescLeft">&#160;</td><td class="mdescRight">Fast approximation to the trigonometric cosine function for Q15 data. <a href="#gadfd60c24def501638c0d5db20f4c869b">More...</a><br/></td></tr>
<tr class="separator:gadfd60c24def501638c0d5db20f4c869b"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:gad80f121949ef885a77d83ab36e002567"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__cos.html#gad80f121949ef885a77d83ab36e002567">arm_cos_q31</a> (<a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a> x)</td></tr>
<tr class="memdesc:gad80f121949ef885a77d83ab36e002567"><td class="mdescLeft">&#160;</td><td class="mdescRight">Fast approximation to the trigonometric cosine function for Q31 data. <a href="#gad80f121949ef885a77d83ab36e002567">More...</a><br/></td></tr>
<tr class="separator:gad80f121949ef885a77d83ab36e002567"><td class="memSeparator" colspan="2">&#160;</td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Description</h2>
<p>Computes the trigonometric cosine function using a combination of table lookup and linear interpolation. There are separate functions for Q15, Q31, and floating-point data types. The input to the floating-point version is in radians while the fixed-point Q15 and Q31 have a scaled input with the range [0 +0.9999] mapping to [0 2*pi). The fixed-point range is chosen so that a value of 2*pi wraps around to 0.</p>
<p>The implementation is based on table lookup using 256 values together with linear interpolation. The steps used are:</p>
<ol type="1">
<li>Calculation of the nearest integer table index</li>
<li>Compute the fractional portion (fract) of the table index.</li>
<li>The final result equals <code>(1.0f-fract)*a + fract*b;</code></li>
</ol>
<p>where </p>
<pre>
b=Table[index+0];
c=Table[index+1];
</pre> <h2 class="groupheader">Function Documentation</h2>
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<td class="memname"><a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a> arm_cos_f32 </td>
<td>(</td>
<td class="paramtype"><a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a>&#160;</td>
<td class="paramname"><em>x</em></td><td>)</td>
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<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">x</td><td>input value in radians. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>cos(x). </dd></dl>
<p>References <a class="el" href="arm__math_8h.html#afcb9147c96853bea484cfc2dde07463d">FAST_MATH_TABLE_SIZE</a>, and <a class="el" href="arm__common__tables_8h.html#a1dec82d596780f1a66ef4f76f137c1d9">sinTable_f32</a>.</p>
<p>Referenced by <a class="el" href="arm__sin__cos__example__f32_8c.html#a52d2cba30e6946c95578be946ac12a65">main()</a>.</p>
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<td class="memname"><a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> arm_cos_q15 </td>
<td>(</td>
<td class="paramtype"><a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a>&#160;</td>
<td class="paramname"><em>x</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">x</td><td>Scaled input value in radians. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>cos(x).</dd></dl>
<p>The Q15 input value is in the range [0 +0.9999] and is mapped to a radian value in the range [0 2*pi). </p>
<p>References <a class="el" href="arm__math_8h.html#a34716b73c631e65e8dd855e08384ecb2">FAST_MATH_Q15_SHIFT</a>, and <a class="el" href="arm__common__tables_8h.html#a9cbcfe313f61add745ebfeddb4fecd55">sinTable_q15</a>.</p>
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<td class="memname"><a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a> arm_cos_q31 </td>
<td>(</td>
<td class="paramtype"><a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a>&#160;</td>
<td class="paramname"><em>x</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">x</td><td>Scaled input value in radians. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>cos(x).</dd></dl>
<p>The Q31 input value is in the range [0 +0.9999] and is mapped to a radian value in the range [0 2*pi). </p>
<p>References <a class="el" href="arm__math_8h.html#a4268f77b1811a0c7fc2532a0bf6108b0">FAST_MATH_Q31_SHIFT</a>, and <a class="el" href="arm__common__tables_8h.html#a8bfccee9e1c0042cf4a765f4b19d097d">sinTable_q31</a>.</p>
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