mirror of
https://gitee.com/mirrors_PX4/PX4-Autopilot.git
synced 2026-04-14 10:07:39 +08:00
160 lines
8.2 KiB
HTML
160 lines
8.2 KiB
HTML
<!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/xhtml;charset=UTF-8"/>
|
|
<title>Variance Example</title>
|
|
<link href="tabs.css" rel="stylesheet" type="text/css"/>
|
|
<link href="cmsis.css" rel="stylesheet" type="text/css" />
|
|
<link href="navtree.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="jquery.js"></script>
|
|
<script type="text/javascript" src="resize.js"></script>
|
|
<script type="text/javascript" src="navtree.js"></script>
|
|
<script type="text/javascript">
|
|
$(document).ready(initResizable);
|
|
</script>
|
|
<link href="search/search.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="search/search.js"></script>
|
|
<script type="text/javascript">
|
|
$(document).ready(function() { searchBox.OnSelectItem(0); });
|
|
</script>
|
|
|
|
</head>
|
|
<body>
|
|
<div id="top"><!-- do not remove this div! -->
|
|
|
|
<div id="titlearea">
|
|
<table cellspacing="0" cellpadding="0">
|
|
<tbody>
|
|
<tr style="height: 46px;">
|
|
<td id="proglogo"><img alt="CMSIS Logo" src="CMSIS_Logo_Final.png"></td>
|
|
|
|
<td style="padding-left: 0.5em;">
|
|
<div id="projectname">CMSIS-DSP
|
|
 <span id="projectnumber">Verison 1.1.0</span>
|
|
</div>
|
|
<div id="projectbrief">CMSIS DSP Software Library</div>
|
|
</td>
|
|
|
|
|
|
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<div id="CMSISnav" class="tabs1">
|
|
<ul class="tablist">
|
|
<li><a href="../../General/html/index.html"><span>CMSIS</span></a></li>
|
|
<li><a href="../../Core/html/index.html"><span>CORE</span></a></li>
|
|
<li class="current"><a href="../../DSP/html/index.html"><span>DSP</span></a></li>
|
|
<li><a href="../../RTOS/html/index.html"><span>RTOS API</span></a></li>
|
|
<li><a href="../../SVD/html/index.html"><span>SVD</span></a></li>
|
|
</ul>
|
|
</div>
|
|
<!-- Generated by Doxygen 1.7.5.1 -->
|
|
<script type="text/javascript">
|
|
var searchBox = new SearchBox("searchBox", "search",false,'Search');
|
|
</script>
|
|
<div id="navrow1" class="tabs">
|
|
<ul class="tablist">
|
|
<li><a href="index.html"><span>Main Page</span></a></li>
|
|
<li><a href="modules.html"><span>Reference</span></a></li>
|
|
<li>
|
|
<div id="MSearchBox" class="MSearchBoxInactive">
|
|
<span class="left">
|
|
<img id="MSearchSelect" src="search/mag_sel.png"
|
|
onmouseover="return searchBox.OnSearchSelectShow()"
|
|
onmouseout="return searchBox.OnSearchSelectHide()"
|
|
alt=""/>
|
|
<input type="text" id="MSearchField" value="Search" accesskey="S"
|
|
onfocus="searchBox.OnSearchFieldFocus(true)"
|
|
onblur="searchBox.OnSearchFieldFocus(false)"
|
|
onkeyup="searchBox.OnSearchFieldChange(event)"/>
|
|
</span><span class="right">
|
|
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
|
|
</span>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div id="side-nav" class="ui-resizable side-nav-resizable">
|
|
<div id="nav-tree">
|
|
<div id="nav-tree-contents">
|
|
</div>
|
|
</div>
|
|
<div id="splitbar" style="-moz-user-select:none;"
|
|
class="ui-resizable-handle">
|
|
</div>
|
|
</div>
|
|
<script type="text/javascript">
|
|
initNavTree('group___variance_example.html','');
|
|
</script>
|
|
<div id="doc-content">
|
|
<div class="header">
|
|
<div class="headertitle">
|
|
<div class="title">Variance Example</div> </div>
|
|
<div class="ingroups"><a class="el" href="group__group_examples.html">Examples</a></div></div>
|
|
<div class="contents">
|
|
<dl class="user"><dt><b>Description: </b></dt><dd></dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd>Demonstrates the use of Basic Math and Support Functions to calculate the variance of an input sequence with N samples. Uniformly distributed white noise is taken as input.</dd></dl>
|
|
<dl class="user"><dt><b>Algorithm:</b></dt><dd></dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd>The variance of a sequence is the mean of the squared deviation of the sequence from its mean. </dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd>This is denoted by the following equation: <pre> variance = ((x[0] - x') * (x[0] - x') + (x[1] - x') * (x[1] - x') + ... + * (x[n-1] - x') * (x[n-1] - x')) / (N-1)</pre> where, <code>x[n]</code> is the input sequence, <code>N</code> is the number of input samples, and <code>x'</code> is the mean value of the input sequence, <code>x[n]</code>. </dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd>The mean value <code>x'</code> is defined as: <pre> x' = (x[0] + x[1] + ... + x[n-1]) / N</pre></dd></dl>
|
|
<dl class="user"><dt><b>Block Diagram:</b></dt><dd></dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd><div class="image">
|
|
<img src="Variance.gif" alt="Variance.gif"/>
|
|
</div>
|
|
</dd></dl>
|
|
<dl class="user"><dt><b>Variables Description:</b></dt><dd></dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd><ul>
|
|
<li><code>testInput_f32</code> points to the input data </li>
|
|
<li><code>wire1</code>, <code>wir2</code>, <code>wire3</code> temporary buffers </li>
|
|
<li><code>blockSize</code> number of samples processed at a time </li>
|
|
<li><code>refVarianceOut</code> reference variance value</li>
|
|
</ul>
|
|
</dd></dl>
|
|
<dl class="user"><dt><b>CMSIS DSP Software Library Functions Used:</b></dt><dd></dd></dl>
|
|
<dl class="user"><dt><b></b></dt><dd><ul>
|
|
<li><a class="el" href="group__dot__prod.html#ga55418d4362f6ba84c327f9b4f089a8c3" title="Dot product of floating-point vectors.">arm_dot_prod_f32()</a></li>
|
|
<li><a class="el" href="group___basic_mult.html#gaca3f0b8227da431ab29225b88888aa32" title="Floating-point vector multiplication.">arm_mult_f32()</a></li>
|
|
<li><a class="el" href="group___basic_sub.html#ga7f975a472de286331134227c08aad826" title="Floating-point vector subtraction.">arm_sub_f32()</a></li>
|
|
<li><a class="el" href="group___fill.html#ga2248e8d3901b4afb7827163132baad94" title="Fills a constant value into a floating-point vector.">arm_fill_f32()</a></li>
|
|
<li><a class="el" href="group__copy.html#gadd1f737e677e0e6ca31767c7001417b3" title="Copies the elements of a floating-point vector.">arm_copy_f32()</a></li>
|
|
</ul>
|
|
</dd></dl>
|
|
<p><b> Refer </b> <a class="el" href="arm_variance_example_f32_8c-example.html">arm_variance_example_f32.c</a> </p>
|
|
</div>
|
|
</div>
|
|
<div id="nav-path" class="navpath">
|
|
<ul>
|
|
<!-- window showing the filter options -->
|
|
<div id="MSearchSelectWindow"
|
|
onmouseover="return searchBox.OnSearchSelectShow()"
|
|
onmouseout="return searchBox.OnSearchSelectHide()"
|
|
onkeydown="return searchBox.OnSearchSelectKey(event)">
|
|
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Data Structures</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark"> </span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark"> </span>Enumerator</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark"> </span>Defines</a></div>
|
|
|
|
<!-- iframe showing the search results (closed by default) -->
|
|
<div id="MSearchResultsWindow">
|
|
<iframe src="javascript:void(0)" frameborder="0"
|
|
name="MSearchResults" id="MSearchResults">
|
|
</iframe>
|
|
</div>
|
|
|
|
|
|
<li class="footer">Generated on Wed Mar 28 2012 15:38:08 for CMSIS-DSP by ARM Ltd. All rights reserved.
|
|
<!--
|
|
<a href="http://www.doxygen.org/index.html">
|
|
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.7.5.1 </li>
|
|
-->
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
|
|
|
|
</body>
|
|
</html>
|