<!doctype html>
<html lang="zh-CN" data-theme="light">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width,initial-scale=1" />
    <meta name="generator" content="VuePress 2.0.0-rc.9" />
    <meta name="theme" content="VuePress Theme Hope 2.0.0-rc.34" />
    <style>
      html {
        background: var(--bg-color, #fff);
      }

      html[data-theme="dark"] {
        background: var(--bg-color, #1d1e1f);
      }

      body {
        background: var(--bg-color);
      }
    </style>
    <script>
      const userMode = localStorage.getItem("vuepress-theme-hope-scheme");
      const systemDarkMode =
        window.matchMedia &&
        window.matchMedia("(prefers-color-scheme: dark)").matches;

      if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) {
        document.documentElement.setAttribute("data-theme", "dark");
      }
    </script>
    <link rel="alternate" hreflang="en-us" href="https://iotdb.apache.org/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html"><meta property="og:url" content="https://iotdb.apache.org/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html"><meta property="og:site_name" content="IoTDB Website"><meta property="og:description" content="频域分析 Conv 函数简介 本函数对两个输入序列进行卷积，即多项式乘法。 函数名： CONV 输入序列： 仅支持两个输入序列，类型均为 INT32 / INT64 / FLOAT / DOUBLE 输出序列： 输出单个序列，类型为DOUBLE，它是两个序列卷积的结果。序列的时间戳从0开始，仅用于表示顺序。 提示： 输入序列中的NaN将被忽略。 使用示..."><meta property="og:type" content="article"><meta property="og:locale" content="zh-CN"><meta property="og:locale:alternate" content="en-US"><meta property="og:updated_time" content="2023-07-10T03:11:17.000Z"><meta property="article:modified_time" content="2023-07-10T03:11:17.000Z"><script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"","image":[""],"dateModified":"2023-07-10T03:11:17.000Z","author":[]}</script><link rel="icon" href="/favicon.ico"><meta name="Description" content="Apache IoTDB: Time Series Database for IoT"><meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据"><meta name="baidu-site-verification" content="wfKETzB3OT"><meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo"><script type="text/javascript">
var _paq = window._paq = window._paq || [];
/* tracker methods like "setCustomDimension" should be called before "trackPageView" */
_paq.push(["setDoNotTrack", true]);
_paq.push(["disableCookies"]);
_paq.push(['trackPageView']);
_paq.push(['enableLinkTracking']);
(function() {
  var u="https://analytics.apache.org/";
  _paq.push(['setTrackerUrl', u+'matomo.php']);
  _paq.push(['setSiteId', '56']);
  var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
  g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s);
})();
       </script><title>IoTDB Website</title><meta name="description" content="频域分析 Conv 函数简介 本函数对两个输入序列进行卷积，即多项式乘法。 函数名： CONV 输入序列： 仅支持两个输入序列，类型均为 INT32 / INT64 / FLOAT / DOUBLE 输出序列： 输出单个序列，类型为DOUBLE，它是两个序列卷积的结果。序列的时间戳从0开始，仅用于表示顺序。 提示： 输入序列中的NaN将被忽略。 使用示...">
    <link rel="preload" href="/assets/style-DnEHAOmf.css" as="style"><link rel="stylesheet" href="/assets/style-DnEHAOmf.css">
    <link rel="modulepreload" href="/assets/app-0jI7BR7G.js"><link rel="modulepreload" href="/assets/Frequency-Domain.html-COpoBwZS.js">
    
  </head>
  <body>
    <div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="vp-skip-link sr-only">跳至主要內容</a><!--]--><!--[--><div class="theme-container has-toc"><!--[--><header id="navbar" class="vp-navbar hide-icon"><div class="vp-navbar-start"><button type="button" class="vp-toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><!----><!--]--><!--[--><a class="route-link vp-brand" href="/zh/"><img class="vp-nav-logo" src="/logo.png" alt><!----><span class="vp-site-name hide-in-pad">IoTDB Website</span></a><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-center"><!--[--><!----><!--]--><!--[--><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-end"><!--[--><!----><!--]--><!--[--><!--[--><div id="docsearch-container" style="display:none;"></div><div><button type="button" class="DocSearch DocSearch-Button" aria-label="搜索文档"><span class="DocSearch-Button-Container"><svg width="20" height="20" class="DocSearch-Search-Icon" viewBox="0 0 20 20"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">搜索文档</span></span><span class="DocSearch-Button-Keys"><kbd class="DocSearch-Button-Key"><svg width="15" height="15" class="DocSearch-Control-Key-Icon"><path d="M4.505 4.496h2M5.505 5.496v5M8.216 4.496l.055 5.993M10 7.5c.333.333.5.667.5 1v2M12.326 4.5v5.996M8.384 4.496c1.674 0 2.116 0 2.116 1.5s-.442 1.5-2.116 1.5M3.205 9.303c-.09.448-.277 1.21-1.241 1.203C1 10.5.5 9.513.5 8V7c0-1.57.5-2.5 1.464-2.494.964.006 1.134.598 1.24 1.342M12.553 10.5h1.953" stroke-width="1.2" stroke="currentColor" fill="none" stroke-linecap="square"></path></svg></kbd><kbd class="DocSearch-Button-Key">K</kbd></span></button></div><!--]--><nav class="vp-nav-links"><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="文档"><span class="title"><!---->文档</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/latest/QuickStart/QuickStart.html" aria-label="v1.3.x"><!---->v1.3.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.2.x/QuickStart/QuickStart.html" aria-label="v1.2.x"><!---->v1.2.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.1.x/QuickStart/QuickStart.html" aria-label="v1.1.x"><!---->v1.1.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.0.x/QuickStart/QuickStart.html" aria-label="v1.0.x"><!---->v1.0.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V0.13.x/QuickStart/QuickStart.html" aria-label="v0.13.x"><!---->v0.13.x<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=177051872" rel="noopener noreferrer" target="_blank" aria-label="系统设计" class="nav-link"><!---->系统设计<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="vp-nav-item hide-in-mobile"><a class="route-link nav-link" href="/zh/Download/" aria-label="下载"><!---->下载<!----></a></div><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="社区"><span class="title"><!---->社区</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/About.html" aria-label="关于社区"><!---->关于社区<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Development-Guide.html" aria-label="贡献指南"><!---->贡献指南<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Powered-By.html" aria-label="社区伙伴"><!---->社区伙伴<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Feedback.html" aria-label="交流与反馈"><!---->交流与反馈<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Materials.html" aria-label="活动与报告"><!---->活动与报告<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Community-Project-Committers.html" aria-label="Commiters"><!---->Commiters<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="ASF"><span class="title"><!---->ASF</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="https://www.apache.org/" rel="noopener noreferrer" target="_blank" aria-label="基金会" class="nav-link"><!---->基金会<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/licenses/" rel="noopener noreferrer" target="_blank" aria-label="许可证" class="nav-link"><!---->许可证<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/security/" rel="noopener noreferrer" target="_blank" aria-label="安全" class="nav-link"><!---->安全<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/sponsorship.html" rel="noopener noreferrer" target="_blank" aria-label="赞助" class="nav-link"><!---->赞助<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/thanks.html" rel="noopener noreferrer" target="_blank" aria-label="致谢" class="nav-link"><!---->致谢<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/events/current-event" rel="noopener noreferrer" target="_blank" aria-label="活动" class="nav-link"><!---->活动<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://privacy.apache.org/policies/privacy-policy-public.html" rel="noopener noreferrer" target="_blank" aria-label="隐私" class="nav-link"><!---->隐私<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li></ul></button></div></div></nav><div class="vp-nav-item"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="选择语言"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon i18n-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="i18n icon" style="width:1rem;height:1rem;vertical-align:middle;"><path d="M379.392 460.8 494.08 575.488l-42.496 102.4L307.2 532.48 138.24 701.44l-71.68-72.704L234.496 460.8l-45.056-45.056c-27.136-27.136-51.2-66.56-66.56-108.544h112.64c7.68 14.336 16.896 27.136 26.112 35.84l45.568 46.08 45.056-45.056C382.976 312.32 409.6 247.808 409.6 204.8H0V102.4h256V0h102.4v102.4h256v102.4H512c0 70.144-37.888 161.28-87.04 210.944L378.88 460.8zM576 870.4 512 1024H409.6l256-614.4H768l256 614.4H921.6l-64-153.6H576zM618.496 768h196.608L716.8 532.48 618.496 768z"></path></svg><!--]--><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html" aria-label="English"><!---->English<!----></a></li><li class="dropdown-item"><a class="route-link nav-link active" href="/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html" aria-label="简体中文"><!---->简体中文<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><button type="button" id="appearance-switch"><svg xmlns="http://www.w3.org/2000/svg" class="icon auto-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="auto icon" style="display:none;"><path d="M512 992C246.92 992 32 777.08 32 512S246.92 32 512 32s480 214.92 480 480-214.92 480-480 480zm0-840c-198.78 0-360 161.22-360 360 0 198.84 161.22 360 360 360s360-161.16 360-360c0-198.78-161.22-360-360-360zm0 660V212c165.72 0 300 134.34 300 300 0 165.72-134.28 300-300 300z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="dark icon" style="display:none;"><path d="M524.8 938.667h-4.267a439.893 439.893 0 0 1-313.173-134.4 446.293 446.293 0 0 1-11.093-597.334A432.213 432.213 0 0 1 366.933 90.027a42.667 42.667 0 0 1 45.227 9.386 42.667 42.667 0 0 1 10.24 42.667 358.4 358.4 0 0 0 82.773 375.893 361.387 361.387 0 0 0 376.747 82.774 42.667 42.667 0 0 1 54.187 55.04 433.493 433.493 0 0 1-99.84 154.88 438.613 438.613 0 0 1-311.467 128z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="light icon" style="display:block;"><path d="M952 552h-80a40 40 0 0 1 0-80h80a40 40 0 0 1 0 80zM801.88 280.08a41 41 0 0 1-57.96-57.96l57.96-58a41.04 41.04 0 0 1 58 58l-58 57.96zM512 752a240 240 0 1 1 0-480 240 240 0 0 1 0 480zm0-560a40 40 0 0 1-40-40V72a40 40 0 0 1 80 0v80a40 40 0 0 1-40 40zm-289.88 88.08-58-57.96a41.04 41.04 0 0 1 58-58l57.96 58a41 41 0 0 1-57.96 57.96zM192 512a40 40 0 0 1-40 40H72a40 40 0 0 1 0-80h80a40 40 0 0 1 40 40zm30.12 231.92a41 41 0 0 1 57.96 57.96l-57.96 58a41.04 41.04 0 0 1-58-58l58-57.96zM512 832a40 40 0 0 1 40 40v80a40 40 0 0 1-80 0v-80a40 40 0 0 1 40-40zm289.88-88.08 58 57.96a41.04 41.04 0 0 1-58 58l-57.96-58a41 41 0 0 1 57.96-57.96z"></path></svg></button></div><div class="vp-nav-item vp-action"><a class="vp-action-link" href="https://github.com/apache/iotdb" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><!--]--><!--[--><!----><!--]--><button type="button" class="vp-toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span><span class="vp-top"></span><span class="vp-middle"></span><span class="vp-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside id="sidebar" class="vp-sidebar"><!--[--><!----><!--]--><ul class="vp-sidebar-links"><li><section class="vp-sidebar-group"><p class="vp-sidebar-header"><!----><span class="vp-sidebar-title">IoTDB用户手册 (V0.13.x)</span><!----></p><ul class="vp-sidebar-links"></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">IoTDB简介</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">快速上手</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据模式与概念</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">语法约定</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">应用编程接口</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">元数据操作</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据写入和删除</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据查询</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据处理</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">权限管理</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">运维工具</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">系统集成</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable active" type="button"><!----><span class="vp-sidebar-title">UDF 资料库</span><span class="vp-arrow down"></span></button><ul class="vp-sidebar-links"><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Quick-Start.html" aria-label="快速开始"><!---->快速开始<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Profiling.html" aria-label="数据画像"><!---->数据画像<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Anomaly-Detection.html" aria-label="异常检测"><!---->异常检测<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Matching.html" aria-label="数据匹配"><!---->数据匹配<!----></a></li><li><a class="route-link nav-link active vp-sidebar-link vp-sidebar-page active" href="/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html" aria-label="频域分析"><!---->频域分析<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Quality.html" aria-label="数据质量"><!---->数据质量<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Repairing.html" aria-label="数据修复"><!---->数据修复<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/Series-Discovery.html" aria-label="序列发现"><!---->序列发现<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V0.13.x/UDF-Library/String-Processing.html" aria-label="字符串处理"><!---->字符串处理<!----></a></li></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">参考</span><span class="vp-arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main id="main-content" class="vp-page"><!--[--><!--[--><!----><!--]--><!----><nav class="vp-breadcrumb disable"></nav><div class="vp-page-title"><h1><!----></h1><div class="page-info"><!----><!----><span class="page-date-info" aria-label="写作日期"><svg xmlns="http://www.w3.org/2000/svg" class="icon calendar-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="calendar icon"><path d="M716.4 110.137c0-18.753-14.72-33.473-33.472-33.473-18.753 0-33.473 14.72-33.473 33.473v33.473h66.993v-33.473zm-334.87 0c0-18.753-14.72-33.473-33.473-33.473s-33.52 14.72-33.52 33.473v33.473h66.993v-33.473zm468.81 33.52H716.4v100.465c0 18.753-14.72 33.473-33.472 33.473a33.145 33.145 0 01-33.473-33.473V143.657H381.53v100.465c0 18.753-14.72 33.473-33.473 33.473a33.145 33.145 0 01-33.473-33.473V143.657H180.6A134.314 134.314 0 0046.66 277.595v535.756A134.314 134.314 0 00180.6 947.289h669.74a134.36 134.36 0 00133.94-133.938V277.595a134.314 134.314 0 00-133.94-133.938zm33.473 267.877H147.126a33.145 33.145 0 01-33.473-33.473c0-18.752 14.72-33.473 33.473-33.473h736.687c18.752 0 33.472 14.72 33.472 33.473a33.145 33.145 0 01-33.472 33.473z"></path></svg><span><!----></span><meta property="datePublished" content="2023-07-10T03:11:17.000Z"></span><span class="page-pageview-info" aria-label="访问量"><svg xmlns="http://www.w3.org/2000/svg" class="icon eye-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="eye icon"><path d="M992 512.096c0-5.76-.992-10.592-1.28-11.136-.192-2.88-1.152-8.064-2.08-10.816-.256-.672-.544-1.376-.832-2.08-.48-1.568-1.024-3.104-1.6-4.32C897.664 290.112 707.104 160 512 160c-195.072 0-385.632 130.016-473.76 322.592-1.056 2.112-1.792 4.096-2.272 5.856a55.512 55.512 0 00-.64 1.6c-1.76 5.088-1.792 8.64-1.632 7.744-.832 3.744-1.568 11.168-1.568 11.168-.224 2.272-.224 4.032.032 6.304 0 0 .736 6.464 1.088 7.808.128 1.824.576 4.512 1.12 6.976h-.032c.448 2.08 1.12 4.096 1.984 6.08.48 1.536.992 2.976 1.472 4.032C126.432 733.856 316.992 864 512 864c195.136 0 385.696-130.048 473.216-321.696 1.376-2.496 2.24-4.832 2.848-6.912.256-.608.48-1.184.672-1.728 1.536-4.48 1.856-8.32 1.728-8.32l-.032.032c.608-3.104 1.568-7.744 1.568-13.28zM512 672c-88.224 0-160-71.776-160-160s71.776-160 160-160 160 71.776 160 160-71.776 160-160 160z"></path></svg><span id="ArtalkPV" class="vp-pageview waline-pageview-count" data-path="/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html" data-page-key="/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.html">...</span></span><span class="page-reading-time-info" aria-label="阅读时间"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>大约 13 分钟</span><meta property="timeRequired" content="PT13M"></span><!----><!----></div><hr></div><div class="vp-toc-placeholder"><aside id="toc"><!--[--><!----><!--]--><div class="vp-toc-header">此页内容<button type="button" class="print-button" title="打印"><svg xmlns="http://www.w3.org/2000/svg" class="icon print-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="print icon"><path d="M819.2 364.8h-44.8V128c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v236.8h-44.8C145.067 364.8 96 413.867 96 473.6v192c0 59.733 49.067 108.8 108.8 108.8h44.8V896c0 17.067 14.933 32 32 32h460.8c17.067 0 32-14.933 32-32V774.4h44.8c59.733 0 108.8-49.067 108.8-108.8v-192c0-59.733-49.067-108.8-108.8-108.8zM313.6 160h396.8v204.8H313.6V160zm396.8 704H313.6V620.8h396.8V864zM864 665.6c0 25.6-19.2 44.8-44.8 44.8h-44.8V588.8c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v121.6h-44.8c-25.6 0-44.8-19.2-44.8-44.8v-192c0-25.6 19.2-44.8 44.8-44.8h614.4c25.6 0 44.8 19.2 44.8 44.8v192z"></path></svg></button><div class="arrow end"></div></div><div class="vp-toc-wrapper"><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#频域分析">频域分析</a></li><li><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#conv">Conv</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#deconv">Deconv</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#dwt">DWT</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#fft">FFT</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#highpass">HighPass</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#ifft">IFFT</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#lowpass">LowPass</a></li><!----><!--]--></ul></li><!--]--></ul><div class="vp-toc-marker" style="top:-1.7rem;"></div></div><!--[--><!----><!--]--></aside></div><!--[--><!----><!--]--><div class="theme-hope-content"><h2 id="频域分析" tabindex="-1"><a class="header-anchor" href="#频域分析"><span>频域分析</span></a></h2><h3 id="conv" tabindex="-1"><a class="header-anchor" href="#conv"><span>Conv</span></a></h3><h4 id="函数简介" tabindex="-1"><a class="header-anchor" href="#函数简介"><span>函数简介</span></a></h4><p>本函数对两个输入序列进行卷积，即多项式乘法。</p><p><strong>函数名：</strong> CONV</p><p><strong>输入序列：</strong> 仅支持两个输入序列，类型均为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE，它是两个序列卷积的结果。序列的时间戳从0开始，仅用于表示顺序。</p><p><strong>提示：</strong> 输入序列中的<code>NaN</code>将被忽略。</p><h4 id="使用示例" tabindex="-1"><a class="header-anchor" href="#使用示例"><span>使用示例</span></a></h4><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+---------------+
|                         Time|root.test.d2.s1|root.test.d2.s2|
+-----------------------------+---------------+---------------+
|1970-01-01T08:00:00.000+08:00|            1.0|            7.0|
|1970-01-01T08:00:00.001+08:00|            0.0|            2.0|
|1970-01-01T08:00:00.002+08:00|            1.0|           null|
+-----------------------------+---------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> conv<span class="token punctuation">(</span>s1<span class="token punctuation">,</span>s2<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d2
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+--------------------------------------+
|                         Time|conv(root.test.d2.s1, root.test.d2.s2)|
+-----------------------------+--------------------------------------+
|1970-01-01T08:00:00.000+08:00|                                   7.0|
|1970-01-01T08:00:00.001+08:00|                                   2.0|
|1970-01-01T08:00:00.002+08:00|                                   7.0|
|1970-01-01T08:00:00.003+08:00|                                   2.0|
+-----------------------------+--------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="deconv" tabindex="-1"><a class="header-anchor" href="#deconv"><span>Deconv</span></a></h3><h4 id="函数简介-1" tabindex="-1"><a class="header-anchor" href="#函数简介-1"><span>函数简介</span></a></h4><p>本函数对两个输入序列进行去卷积，即多项式除法运算。</p><p><strong>函数名：</strong> DECONV</p><p><strong>输入序列：</strong> 仅支持两个输入序列，类型均为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>result</code>：去卷积的结果，取值为&#39;quotient&#39;或&#39;remainder&#39;，分别对应于去卷积的商和余数。在缺省情况下，输出去卷积的商。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE。它是将第二个序列从第一个序列中去卷积（第一个序列除以第二个序列）的结果。序列的时间戳从0开始，仅用于表示顺序。</p><p><strong>提示：</strong> 输入序列中的<code>NaN</code>将被忽略。</p><h4 id="使用示例-1" tabindex="-1"><a class="header-anchor" href="#使用示例-1"><span>使用示例</span></a></h4><h5 id="计算去卷积的商" tabindex="-1"><a class="header-anchor" href="#计算去卷积的商"><span>计算去卷积的商</span></a></h5><p>当<code>result</code>参数缺省或为&#39;quotient&#39;时，本函数计算去卷积的商。</p><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+---------------+
|                         Time|root.test.d2.s3|root.test.d2.s2|
+-----------------------------+---------------+---------------+
|1970-01-01T08:00:00.000+08:00|            8.0|            7.0|
|1970-01-01T08:00:00.001+08:00|            2.0|            2.0|
|1970-01-01T08:00:00.002+08:00|            7.0|           null|
|1970-01-01T08:00:00.003+08:00|            2.0|           null|
+-----------------------------+---------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> deconv<span class="token punctuation">(</span>s3<span class="token punctuation">,</span>s2<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d2
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+----------------------------------------+
|                         Time|deconv(root.test.d2.s3, root.test.d2.s2)|
+-----------------------------+----------------------------------------+
|1970-01-01T08:00:00.000+08:00|                                     1.0|
|1970-01-01T08:00:00.001+08:00|                                     0.0|
|1970-01-01T08:00:00.002+08:00|                                     1.0|
+-----------------------------+----------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h5 id="计算去卷积的余数" tabindex="-1"><a class="header-anchor" href="#计算去卷积的余数"><span>计算去卷积的余数</span></a></h5><p>当<code>result</code>参数为&#39;remainder&#39;时，本函数计算去卷积的余数。输入序列同上，用于查询的SQL语句如下：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> deconv<span class="token punctuation">(</span>s3<span class="token punctuation">,</span>s2<span class="token punctuation">,</span><span class="token string">&#39;result&#39;</span><span class="token operator">=</span><span class="token string">&#39;remainder&#39;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d2
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+--------------------------------------------------------------+
|                         Time|deconv(root.test.d2.s3, root.test.d2.s2, &quot;result&quot;=&quot;remainder&quot;)|
+-----------------------------+--------------------------------------------------------------+
|1970-01-01T08:00:00.000+08:00|                                                           1.0|
|1970-01-01T08:00:00.001+08:00|                                                           0.0|
|1970-01-01T08:00:00.002+08:00|                                                           0.0|
|1970-01-01T08:00:00.003+08:00|                                                           0.0|
+-----------------------------+--------------------------------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="dwt" tabindex="-1"><a class="header-anchor" href="#dwt"><span>DWT</span></a></h3><h4 id="函数简介-2" tabindex="-1"><a class="header-anchor" href="#函数简介-2"><span>函数简介</span></a></h4><p>本函数对输入序列进行一维离散小波变换。</p><p><strong>函数名：</strong> DWT</p><p><strong>输入序列：</strong> 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>method</code>：小波滤波的类型，提供&#39;Haar&#39;, &#39;DB4&#39;, &#39;DB6&#39;, &#39;DB8&#39;，其中DB指代Daubechies。若不设置该参数，则用户需提供小波滤波的系数。不区分大小写。</li><li><code>coef</code>：小波滤波的系数。若提供该参数，请使用英文逗号&#39;,&#39;分割各项，不添加空格或其它符号。</li><li><code>layer</code>：进行变换的次数，最终输出的向量个数等同于$layer+1$.默认取1。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE，长度与输入相等。</p><p><strong>提示：</strong> 输入序列长度必须为2的整数次幂。</p><h4 id="使用示例-2" tabindex="-1"><a class="header-anchor" href="#使用示例-2"><span>使用示例</span></a></h4><h5 id="haar变换" tabindex="-1"><a class="header-anchor" href="#haar变换"><span>Haar变换</span></a></h5><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+
|                         Time|root.test.d1.s1|
+-----------------------------+---------------+
|1970-01-01T08:00:00.000+08:00|            0.0|
|1970-01-01T08:00:00.100+08:00|            0.2|
|1970-01-01T08:00:00.200+08:00|            1.5|
|1970-01-01T08:00:00.300+08:00|            1.2|
|1970-01-01T08:00:00.400+08:00|            0.6|
|1970-01-01T08:00:00.500+08:00|            1.7|
|1970-01-01T08:00:00.600+08:00|            0.8|
|1970-01-01T08:00:00.700+08:00|            2.0|
|1970-01-01T08:00:00.800+08:00|            2.5|
|1970-01-01T08:00:00.900+08:00|            2.1|
|1970-01-01T08:00:01.000+08:00|            0.0|
|1970-01-01T08:00:01.100+08:00|            2.0|
|1970-01-01T08:00:01.200+08:00|            1.8|
|1970-01-01T08:00:01.300+08:00|            1.2|
|1970-01-01T08:00:01.400+08:00|            1.0|
|1970-01-01T08:00:01.500+08:00|            1.6|
+-----------------------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> dwt<span class="token punctuation">(</span>s1<span class="token punctuation">,</span><span class="token string">&quot;method&quot;</span><span class="token operator">=</span><span class="token string">&quot;haar&quot;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+-------------------------------------+
|                         Time|dwt(root.test.d1.s1, &quot;method&quot;=&quot;haar&quot;)|
+-----------------------------+-------------------------------------+
|1970-01-01T08:00:00.000+08:00|                  0.14142135834465192|
|1970-01-01T08:00:00.100+08:00|                    1.909188342921157|
|1970-01-01T08:00:00.200+08:00|                   1.6263456473052773|
|1970-01-01T08:00:00.300+08:00|                   1.9798989957517026|
|1970-01-01T08:00:00.400+08:00|                    3.252691126023161|
|1970-01-01T08:00:00.500+08:00|                    1.414213562373095|
|1970-01-01T08:00:00.600+08:00|                   2.1213203435596424|
|1970-01-01T08:00:00.700+08:00|                   1.8384776479437628|
|1970-01-01T08:00:00.800+08:00|                 -0.14142135834465192|
|1970-01-01T08:00:00.900+08:00|                  0.21213200063848547|
|1970-01-01T08:00:01.000+08:00|                  -0.7778174761639416|
|1970-01-01T08:00:01.100+08:00|                  -0.8485281289944873|
|1970-01-01T08:00:01.200+08:00|                   0.2828427799095765|
|1970-01-01T08:00:01.300+08:00|                   -1.414213562373095|
|1970-01-01T08:00:01.400+08:00|                  0.42426400127697095|
|1970-01-01T08:00:01.500+08:00|                 -0.42426408557066786|
+-----------------------------+-------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="fft" tabindex="-1"><a class="header-anchor" href="#fft"><span>FFT</span></a></h3><h4 id="函数简介-3" tabindex="-1"><a class="header-anchor" href="#函数简介-3"><span>函数简介</span></a></h4><p>本函数对输入序列进行快速傅里叶变换。</p><p><strong>函数名：</strong> FFT</p><p><strong>输入序列：</strong> 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>method</code>：傅里叶变换的类型，取值为&#39;uniform&#39;或&#39;nonuniform&#39;，缺省情况下为&#39;uniform&#39;。当取值为&#39;uniform&#39;时，时间戳将被忽略，所有数据点都将被视作等距的，并应用等距快速傅里叶算法；当取值为&#39;nonuniform&#39;时，将根据时间戳应用非等距快速傅里叶算法（未实现）。</li><li><code>result</code>：傅里叶变换的结果，取值为&#39;real&#39;、&#39;imag&#39;、&#39;abs&#39;或&#39;angle&#39;，分别对应于变换结果的实部、虚部、模和幅角。在缺省情况下，输出变换的模。</li><li><code>compress</code>：压缩参数，取值范围(0,1]，是有损压缩时保留的能量比例。在缺省情况下，不进行压缩。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE，长度与输入相等。序列的时间戳从0开始，仅用于表示顺序。</p><p><strong>提示：</strong> 输入序列中的<code>NaN</code>将被忽略。</p><h4 id="使用示例-3" tabindex="-1"><a class="header-anchor" href="#使用示例-3"><span>使用示例</span></a></h4><h5 id="等距傅里叶变换" tabindex="-1"><a class="header-anchor" href="#等距傅里叶变换"><span>等距傅里叶变换</span></a></h5><p>当<code>type</code>参数缺省或为&#39;uniform&#39;时，本函数进行等距傅里叶变换。</p><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+
|                         Time|root.test.d1.s1|
+-----------------------------+---------------+
|1970-01-01T08:00:00.000+08:00|       2.902113|
|1970-01-01T08:00:01.000+08:00|      1.1755705|
|1970-01-01T08:00:02.000+08:00|     -2.1755705|
|1970-01-01T08:00:03.000+08:00|     -1.9021131|
|1970-01-01T08:00:04.000+08:00|            1.0|
|1970-01-01T08:00:05.000+08:00|      1.9021131|
|1970-01-01T08:00:06.000+08:00|      0.1755705|
|1970-01-01T08:00:07.000+08:00|     -1.1755705|
|1970-01-01T08:00:08.000+08:00|      -0.902113|
|1970-01-01T08:00:09.000+08:00|            0.0|
|1970-01-01T08:00:10.000+08:00|       0.902113|
|1970-01-01T08:00:11.000+08:00|      1.1755705|
|1970-01-01T08:00:12.000+08:00|     -0.1755705|
|1970-01-01T08:00:13.000+08:00|     -1.9021131|
|1970-01-01T08:00:14.000+08:00|           -1.0|
|1970-01-01T08:00:15.000+08:00|      1.9021131|
|1970-01-01T08:00:16.000+08:00|      2.1755705|
|1970-01-01T08:00:17.000+08:00|     -1.1755705|
|1970-01-01T08:00:18.000+08:00|      -2.902113|
|1970-01-01T08:00:19.000+08:00|            0.0|
+-----------------------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> fft<span class="token punctuation">(</span>s1<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+----------------------+
|                         Time|  fft(root.test.d1.s1)|
+-----------------------------+----------------------+
|1970-01-01T08:00:00.000+08:00|                   0.0|
|1970-01-01T08:00:00.001+08:00| 1.2727111142703152E-8|
|1970-01-01T08:00:00.002+08:00|  2.385520799101839E-7|
|1970-01-01T08:00:00.003+08:00|  8.723291723972645E-8|
|1970-01-01T08:00:00.004+08:00|    19.999999960195904|
|1970-01-01T08:00:00.005+08:00|     9.999999850988388|
|1970-01-01T08:00:00.006+08:00| 3.2260694930700566E-7|
|1970-01-01T08:00:00.007+08:00|  8.723291605373329E-8|
|1970-01-01T08:00:00.008+08:00|  1.108657103979944E-7|
|1970-01-01T08:00:00.009+08:00| 1.2727110997246171E-8|
|1970-01-01T08:00:00.010+08:00|1.9852334701272664E-23|
|1970-01-01T08:00:00.011+08:00| 1.2727111194499847E-8|
|1970-01-01T08:00:00.012+08:00|  1.108657103979944E-7|
|1970-01-01T08:00:00.013+08:00|  8.723291785769131E-8|
|1970-01-01T08:00:00.014+08:00|  3.226069493070057E-7|
|1970-01-01T08:00:00.015+08:00|     9.999999850988388|
|1970-01-01T08:00:00.016+08:00|    19.999999960195904|
|1970-01-01T08:00:00.017+08:00|  8.723291747109068E-8|
|1970-01-01T08:00:00.018+08:00| 2.3855207991018386E-7|
|1970-01-01T08:00:00.019+08:00| 1.2727112069910878E-8|
+-----------------------------+----------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>注：输入序列服从$y=sin(2\pi t/4)+2sin(2\pi t/5)$，长度为20，因此在输出序列中$k=4$和$k=5$处有尖峰。</p><h5 id="等距傅里叶变换并压缩" tabindex="-1"><a class="header-anchor" href="#等距傅里叶变换并压缩"><span>等距傅里叶变换并压缩</span></a></h5><p>输入序列同上，用于查询的SQL语句如下：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> fft<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&#39;result&#39;</span><span class="token operator">=</span><span class="token string">&#39;real&#39;</span><span class="token punctuation">,</span> <span class="token string">&#39;compress&#39;</span><span class="token operator">=</span><span class="token string">&#39;0.99&#39;</span><span class="token punctuation">)</span><span class="token punctuation">,</span> fft<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&#39;result&#39;</span><span class="token operator">=</span><span class="token string">&#39;imag&#39;</span><span class="token punctuation">,</span><span class="token string">&#39;compress&#39;</span><span class="token operator">=</span><span class="token string">&#39;0.99&#39;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+----------------------+----------------------+
|                         Time|  fft(root.test.d1.s1,|  fft(root.test.d1.s1,|
|                             |      &quot;result&quot;=&quot;real&quot;,|      &quot;result&quot;=&quot;imag&quot;,|
|                             |    &quot;compress&quot;=&quot;0.99&quot;)|    &quot;compress&quot;=&quot;0.99&quot;)|
+-----------------------------+----------------------+----------------------+
|1970-01-01T08:00:00.000+08:00|                   0.0|                   0.0|
|1970-01-01T08:00:00.001+08:00| -3.932894010461041E-9| 1.2104201863039066E-8|
|1970-01-01T08:00:00.002+08:00|-1.4021739447490164E-7| 1.9299268669082926E-7|
|1970-01-01T08:00:00.003+08:00| -7.057291240286645E-8|  5.127422242345858E-8|
|1970-01-01T08:00:00.004+08:00|    19.021130288047125|    -6.180339875198807|
|1970-01-01T08:00:00.005+08:00|     9.999999850988388| 3.501852745067114E-16|
|1970-01-01T08:00:00.019+08:00| -3.932894898639461E-9|-1.2104202549376264E-8|
+-----------------------------+----------------------+----------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>注：基于傅里叶变换结果的共轭性质，压缩结果只保留前一半；根据给定的压缩参数，从低频到高频保留数据点，直到保留的能量比例超过该值；保留最后一个数据点以表示序列长度。</p><h3 id="highpass" tabindex="-1"><a class="header-anchor" href="#highpass"><span>HighPass</span></a></h3><h4 id="函数简介-4" tabindex="-1"><a class="header-anchor" href="#函数简介-4"><span>函数简介</span></a></h4><p>本函数对输入序列进行高通滤波，提取高于截止频率的分量。输入序列的时间戳将被忽略，所有数据点都将被视作等距的。</p><p><strong>函数名：</strong> HIGHPASS</p><p><strong>输入序列：</strong> 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>wpass</code>：归一化后的截止频率，取值为(0,1)，不可缺省。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE，它是滤波后的序列，长度与时间戳均与输入一致。</p><p><strong>提示：</strong> 输入序列中的<code>NaN</code>将被忽略。</p><h4 id="使用示例-4" tabindex="-1"><a class="header-anchor" href="#使用示例-4"><span>使用示例</span></a></h4><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+
|                         Time|root.test.d1.s1|
+-----------------------------+---------------+
|1970-01-01T08:00:00.000+08:00|       2.902113|
|1970-01-01T08:00:01.000+08:00|      1.1755705|
|1970-01-01T08:00:02.000+08:00|     -2.1755705|
|1970-01-01T08:00:03.000+08:00|     -1.9021131|
|1970-01-01T08:00:04.000+08:00|            1.0|
|1970-01-01T08:00:05.000+08:00|      1.9021131|
|1970-01-01T08:00:06.000+08:00|      0.1755705|
|1970-01-01T08:00:07.000+08:00|     -1.1755705|
|1970-01-01T08:00:08.000+08:00|      -0.902113|
|1970-01-01T08:00:09.000+08:00|            0.0|
|1970-01-01T08:00:10.000+08:00|       0.902113|
|1970-01-01T08:00:11.000+08:00|      1.1755705|
|1970-01-01T08:00:12.000+08:00|     -0.1755705|
|1970-01-01T08:00:13.000+08:00|     -1.9021131|
|1970-01-01T08:00:14.000+08:00|           -1.0|
|1970-01-01T08:00:15.000+08:00|      1.9021131|
|1970-01-01T08:00:16.000+08:00|      2.1755705|
|1970-01-01T08:00:17.000+08:00|     -1.1755705|
|1970-01-01T08:00:18.000+08:00|      -2.902113|
|1970-01-01T08:00:19.000+08:00|            0.0|
+-----------------------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> highpass<span class="token punctuation">(</span>s1<span class="token punctuation">,</span><span class="token string">&#39;wpass&#39;</span><span class="token operator">=</span><span class="token string">&#39;0.45&#39;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+-----------------------------------------+
|                         Time|highpass(root.test.d1.s1, &quot;wpass&quot;=&quot;0.45&quot;)|
+-----------------------------+-----------------------------------------+
|1970-01-01T08:00:00.000+08:00|                       0.9999999534830373|
|1970-01-01T08:00:01.000+08:00|                    1.7462829277628608E-8|
|1970-01-01T08:00:02.000+08:00|                      -0.9999999593178128|
|1970-01-01T08:00:03.000+08:00|                   -4.1115269056426626E-8|
|1970-01-01T08:00:04.000+08:00|                       0.9999999925494194|
|1970-01-01T08:00:05.000+08:00|                     3.328126513330016E-8|
|1970-01-01T08:00:06.000+08:00|                      -1.0000000183304454|
|1970-01-01T08:00:07.000+08:00|                    6.260191433311374E-10|
|1970-01-01T08:00:08.000+08:00|                       1.0000000018134796|
|1970-01-01T08:00:09.000+08:00|                   -3.097210911744423E-17|
|1970-01-01T08:00:10.000+08:00|                      -1.0000000018134794|
|1970-01-01T08:00:11.000+08:00|                   -6.260191627862097E-10|
|1970-01-01T08:00:12.000+08:00|                       1.0000000183304454|
|1970-01-01T08:00:13.000+08:00|                    -3.328126501424346E-8|
|1970-01-01T08:00:14.000+08:00|                      -0.9999999925494196|
|1970-01-01T08:00:15.000+08:00|                     4.111526915498874E-8|
|1970-01-01T08:00:16.000+08:00|                       0.9999999593178128|
|1970-01-01T08:00:17.000+08:00|                   -1.7462829341296528E-8|
|1970-01-01T08:00:18.000+08:00|                      -0.9999999534830369|
|1970-01-01T08:00:19.000+08:00|                   -1.035237222742873E-16|
+-----------------------------+-----------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>注：输入序列服从$y=sin(2\pi t/4)+2sin(2\pi t/5)$，长度为20，因此高通滤波之后的输出序列服从$y=sin(2\pi t/4)$。</p><h3 id="ifft" tabindex="-1"><a class="header-anchor" href="#ifft"><span>IFFT</span></a></h3><h4 id="函数简介-5" tabindex="-1"><a class="header-anchor" href="#函数简介-5"><span>函数简介</span></a></h4><p>本函数将输入的两个序列作为实部和虚部视作一个复数，进行逆快速傅里叶变换，并输出结果的实部。输入数据的格式参见<code>FFT</code>函数的输出，并支持以<code>FFT</code>函数压缩后的输出作为本函数的输入。</p><p><strong>函数名：</strong> IFFT</p><p><strong>输入序列：</strong> 仅支持两个输入序列，类型均为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>start</code>：输出序列的起始时刻，是一个格式为&#39;yyyy-MM-dd HH:mm:ss&#39;的时间字符串。在缺省情况下，为&#39;1970-01-01 08:00:00&#39;。</li><li><code>interval</code>：输出序列的时间间隔，是一个有单位的正数。目前支持五种单位，分别是&#39;ms&#39;（毫秒）、&#39;s&#39;（秒）、&#39;m&#39;（分钟）、&#39;h&#39;（小时）和&#39;d&#39;（天）。在缺省情况下，为1s。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE。该序列是一个等距时间序列，它的值是将两个输入序列依次作为实部和虚部进行逆快速傅里叶变换的结果。</p><p><strong>提示：</strong> 如果某行数据中包含空值或<code>NaN</code>，该行数据将会被忽略。</p><h4 id="使用示例-5" tabindex="-1"><a class="header-anchor" href="#使用示例-5"><span>使用示例</span></a></h4><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+----------------------+----------------------+
|                         Time|       root.test.d1.re|       root.test.d1.im|
+-----------------------------+----------------------+----------------------+
|1970-01-01T08:00:00.000+08:00|                   0.0|                   0.0|
|1970-01-01T08:00:00.001+08:00| -3.932894010461041E-9| 1.2104201863039066E-8|
|1970-01-01T08:00:00.002+08:00|-1.4021739447490164E-7| 1.9299268669082926E-7|
|1970-01-01T08:00:00.003+08:00| -7.057291240286645E-8|  5.127422242345858E-8|
|1970-01-01T08:00:00.004+08:00|    19.021130288047125|    -6.180339875198807|
|1970-01-01T08:00:00.005+08:00|     9.999999850988388| 3.501852745067114E-16|
|1970-01-01T08:00:00.019+08:00| -3.932894898639461E-9|-1.2104202549376264E-8|
+-----------------------------+----------------------+----------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> ifft<span class="token punctuation">(</span>re<span class="token punctuation">,</span> im<span class="token punctuation">,</span> <span class="token string">&#39;interval&#39;</span><span class="token operator">=</span><span class="token string">&#39;1m&#39;</span><span class="token punctuation">,</span> <span class="token string">&#39;start&#39;</span><span class="token operator">=</span><span class="token string">&#39;2021-01-01 00:00:00&#39;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+-------------------------------------------------------+
|                         Time|ifft(root.test.d1.re, root.test.d1.im, &quot;interval&quot;=&quot;1m&quot;,|
|                             |                         &quot;start&quot;=&quot;2021-01-01 00:00:00&quot;)|
+-----------------------------+-------------------------------------------------------+
|2021-01-01T00:00:00.000+08:00|                                      2.902112992431231|
|2021-01-01T00:01:00.000+08:00|                                     1.1755704705132448|
|2021-01-01T00:02:00.000+08:00|                                     -2.175570513757101|
|2021-01-01T00:03:00.000+08:00|                                    -1.9021130389094498|
|2021-01-01T00:04:00.000+08:00|                                     0.9999999925494194|
|2021-01-01T00:05:00.000+08:00|                                      1.902113046743454|
|2021-01-01T00:06:00.000+08:00|                                    0.17557053610884188|
|2021-01-01T00:07:00.000+08:00|                                    -1.1755704886020932|
|2021-01-01T00:08:00.000+08:00|                                    -0.9021130371347148|
|2021-01-01T00:09:00.000+08:00|                                  3.552713678800501E-16|
|2021-01-01T00:10:00.000+08:00|                                     0.9021130371347154|
|2021-01-01T00:11:00.000+08:00|                                     1.1755704886020932|
|2021-01-01T00:12:00.000+08:00|                                   -0.17557053610884144|
|2021-01-01T00:13:00.000+08:00|                                     -1.902113046743454|
|2021-01-01T00:14:00.000+08:00|                                    -0.9999999925494196|
|2021-01-01T00:15:00.000+08:00|                                     1.9021130389094498|
|2021-01-01T00:16:00.000+08:00|                                     2.1755705137571004|
|2021-01-01T00:17:00.000+08:00|                                    -1.1755704705132448|
|2021-01-01T00:18:00.000+08:00|                                     -2.902112992431231|
|2021-01-01T00:19:00.000+08:00|                                 -3.552713678800501E-16|
+-----------------------------+-------------------------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="lowpass" tabindex="-1"><a class="header-anchor" href="#lowpass"><span>LowPass</span></a></h3><h4 id="函数简介-6" tabindex="-1"><a class="header-anchor" href="#函数简介-6"><span>函数简介</span></a></h4><p>本函数对输入序列进行低通滤波，提取低于截止频率的分量。输入序列的时间戳将被忽略，所有数据点都将被视作等距的。</p><p><strong>函数名：</strong> LOWPASS</p><p><strong>输入序列：</strong> 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE</p><p><strong>参数：</strong></p><ul><li><code>wpass</code>：归一化后的截止频率，取值为(0,1)，不可缺省。</li></ul><p><strong>输出序列：</strong> 输出单个序列，类型为DOUBLE，它是滤波后的序列，长度与时间戳均与输入一致。</p><p><strong>提示：</strong> 输入序列中的<code>NaN</code>将被忽略。</p><h4 id="使用示例-6" tabindex="-1"><a class="header-anchor" href="#使用示例-6"><span>使用示例</span></a></h4><p>输入序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+---------------+
|                         Time|root.test.d1.s1|
+-----------------------------+---------------+
|1970-01-01T08:00:00.000+08:00|       2.902113|
|1970-01-01T08:00:01.000+08:00|      1.1755705|
|1970-01-01T08:00:02.000+08:00|     -2.1755705|
|1970-01-01T08:00:03.000+08:00|     -1.9021131|
|1970-01-01T08:00:04.000+08:00|            1.0|
|1970-01-01T08:00:05.000+08:00|      1.9021131|
|1970-01-01T08:00:06.000+08:00|      0.1755705|
|1970-01-01T08:00:07.000+08:00|     -1.1755705|
|1970-01-01T08:00:08.000+08:00|      -0.902113|
|1970-01-01T08:00:09.000+08:00|            0.0|
|1970-01-01T08:00:10.000+08:00|       0.902113|
|1970-01-01T08:00:11.000+08:00|      1.1755705|
|1970-01-01T08:00:12.000+08:00|     -0.1755705|
|1970-01-01T08:00:13.000+08:00|     -1.9021131|
|1970-01-01T08:00:14.000+08:00|           -1.0|
|1970-01-01T08:00:15.000+08:00|      1.9021131|
|1970-01-01T08:00:16.000+08:00|      2.1755705|
|1970-01-01T08:00:17.000+08:00|     -1.1755705|
|1970-01-01T08:00:18.000+08:00|      -2.902113|
|1970-01-01T08:00:19.000+08:00|            0.0|
+-----------------------------+---------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>用于查询的SQL语句：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">select</span> lowpass<span class="token punctuation">(</span>s1<span class="token punctuation">,</span><span class="token string">&#39;wpass&#39;</span><span class="token operator">=</span><span class="token string">&#39;0.45&#39;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<span class="token punctuation">.</span>d1
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>输出序列：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+----------------------------------------+
|                         Time|lowpass(root.test.d1.s1, &quot;wpass&quot;=&quot;0.45&quot;)|
+-----------------------------+----------------------------------------+
|1970-01-01T08:00:00.000+08:00|                      1.9021130073323922|
|1970-01-01T08:00:01.000+08:00|                      1.1755704705132448|
|1970-01-01T08:00:02.000+08:00|                     -1.1755705286582614|
|1970-01-01T08:00:03.000+08:00|                     -1.9021130389094498|
|1970-01-01T08:00:04.000+08:00|                    7.450580419288145E-9|
|1970-01-01T08:00:05.000+08:00|                       1.902113046743454|
|1970-01-01T08:00:06.000+08:00|                      1.1755705212076808|
|1970-01-01T08:00:07.000+08:00|                     -1.1755704886020932|
|1970-01-01T08:00:08.000+08:00|                     -1.9021130222335536|
|1970-01-01T08:00:09.000+08:00|                   3.552713678800501E-16|
|1970-01-01T08:00:10.000+08:00|                      1.9021130222335536|
|1970-01-01T08:00:11.000+08:00|                      1.1755704886020932|
|1970-01-01T08:00:12.000+08:00|                     -1.1755705212076801|
|1970-01-01T08:00:13.000+08:00|                      -1.902113046743454|
|1970-01-01T08:00:14.000+08:00|                    -7.45058112983088E-9|
|1970-01-01T08:00:15.000+08:00|                      1.9021130389094498|
|1970-01-01T08:00:16.000+08:00|                      1.1755705286582616|
|1970-01-01T08:00:17.000+08:00|                     -1.1755704705132448|
|1970-01-01T08:00:18.000+08:00|                     -1.9021130073323924|
|1970-01-01T08:00:19.000+08:00|                  -2.664535259100376E-16|
+-----------------------------+----------------------------------------+
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>注：输入序列服从$y=sin(2\pi t/4)+2sin(2\pi t/5)$，长度为20，因此低通滤波之后的输出序列服从$y=2sin(2\pi t/5)$。</p></div><!--[--><!----><!--]--><footer class="vp-page-meta"><div class="vp-meta-item edit-link"><a href="https://github.com/apache/iotdb-docs/edit/main/src/zh/UserGuide/V0.13.x/UDF-Library/Frequency-Domain.md" rel="noopener noreferrer" target="_blank" aria-label="发现错误？在 GitHub 上编辑此页" class="nav-link vp-meta-label"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->发现错误？在 GitHub 上编辑此页<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="vp-meta-item git-info"><div class="update-time"><span class="vp-meta-label">上次编辑于: </span><!----></div><!----></div></footer><nav class="vp-page-nav"><a class="route-link nav-link prev" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Matching.html" aria-label="数据匹配"><div class="hint"><span class="arrow start"></span>上一页</div><div class="link"><!---->数据匹配</div></a><a class="route-link nav-link next" href="/zh/UserGuide/V0.13.x/UDF-Library/Data-Quality.html" aria-label="数据质量"><div class="hint">下一页<span class="arrow end"></span></div><div class="link">数据质量<!----></div></a></nav><!----><!--[--><!----><!--]--><!--]--></main><!--]--><footer style="padding-bottom:2rem;"><span id="doc-version" style="display:none;">rel/0.13</span><p style="text-align:center;color:#909399;font-size:12px;margin:0 30px;">Copyright © 2024 The Apache Software Foundation.<br> Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"><strong>Have a question?</strong> Connect with us on QQ, WeChat, or Slack. <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> now.</p></footer></div><!--]--><!--]--><!--[--><!----><!--]--><!--]--></div>
    <script type="module" src="/assets/app-0jI7BR7G.js" defer></script>
  </body>
</html>