?? ch7_1_2.htm
字號:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>內插</title>
<meta name="GENERATOR" content="Microsoft FrontPage 3.0">
</head>
<body background="../img3/bg0000.gif">
<script language="JAVASCRIPT">
<!--
if (navigator.onLine){
document.write("<!-- Spidersoft WebZIP Ad Banner Insert -->");
document.write("<TABLE width=100% border=0 cellpadding=0 cellspacing=0>");
document.write("<TR>");
document.write("<TD>");
document.write("<ILAYER id=ad1 visibility=hidden height=60></ILAYER>");
document.write("<NOLAYER>");
document.write("<IFRAME SRC='http://www.spidersoft.com/ads/bwz468_60.htm' width=100% height=60 marginwidth=0 marginheight=0 hspace=0 vspace=0 frameborder=0 scrolling=no></IFRAME>");
document.write("</NOLAYER>");
document.write("</TD>");
document.write("</TR>");
document.write("</TABLE>");
document.write("<!-- End of Spidersoft WebZIP Ad Banner Insert-->");
}
//-->
</script>
<p><font color="#0000FF"><strong><big><big><big>7.1.2 二維內插</big></big></big></strong></font></p>
<hr>
<p>二維內插與一維內插的區別是二維內插數據為二維,語法結構為<font COLOR="#FF0000">interp2(X,Y,Z,XI,YI)</font><font color="#000000">,其中</font><font color="#FF0000">X,Y,Z</font><font color="#000000">為已知數據,</font><i><font FACE="Times New Roman"><font color="#FF0000">Z=Z(X,Y)</font>,</font>而</i><font FACE="Times New Roman"><font color="#FF0000">XI,YI</font> </font>為要插值的數據點<font FACE="Times New Roman">;</font>如果語法結構為<font COLOR="#FF0000">interp2(X,Y,Z,XI,YI,'method')</font><font color="#000000">,其中</font><font COLOR="#FF0000">method</font><font color="#000000">可以為</font><font COLOR="#FF0000">linear</font>,<font COLOR="#FF0000">cubic</font>表示線形或三次方插值,我們以下例說明:</p>
<p>假設一汽車的轉速(單位為:rpm)、溫度（單位為：<font FACE="Times New Roman"><sup>o</sup>C</font>）、時間（單位為：sec）如下表：</p>
<table BORDER="1">
<tr>
<td WIDTH="66">time </td>
<td COLSPAN="3" WIDTH="224">speed </td>
</tr>
<tr>
<td WIDTH="66">0 </td>
<td WIDTH="72">2000 rpm </td>
<td WIDTH="76">3000 rpm </td>
<td WIDTH="76">4000 rpm </td>
</tr>
<tr>
<td WIDTH="66">1 </td>
<td WIDTH="72">20 </td>
<td WIDTH="76">110 </td>
<td WIDTH="76">176 </td>
</tr>
<tr>
<td WIDTH="66">2 </td>
<td WIDTH="72">60 </td>
<td WIDTH="76">180 </td>
<td WIDTH="76">220 </td>
</tr>
<tr>
<td WIDTH="66">3 </td>
<td WIDTH="72">68 </td>
<td WIDTH="76">240 </td>
<td WIDTH="76">349 </td>
</tr>
<tr>
<td WIDTH="66">4 </td>
<td WIDTH="72">77 </td>
<td WIDTH="76">310 </td>
<td WIDTH="76">450 </td>
</tr>
<tr>
<td WIDTH="66">5 </td>
<td WIDTH="72">110 </td>
<td WIDTH="76">405 </td>
<td WIDTH="76">503 </td>
</tr>
</table>
<p>其中溫度的數據為<font FACE="Times New Roman">20<sup>o</sup>C</font>到<font FACE="Times New Roman">50<sup>3o</sup>C</font>，如果要估計<font FACE="Times New Roman">t=2.6, sec, rpm=2500</font>的溫度，可以利用下面的語句：</p>
<p><font COLOR="#FF0000"><font FACE="Times New Roman">>> d2(:,1)=[0 1 2 3 4 5]'; % </font>將時間輸入</font>
<br>
<br>
<font COLOR="#FF0000"><font FACE="Times New Roman">>> d2(:,2)=[2000 20 60 68 77
110]'; % </font>將<font FACE="Times New Roman"> rpm=2000</font>的溫度輸入</font>
<br>
<br>
<font COLOR="#FF0000"><font FACE="Times New Roman">>> d2(:,3)=[3000 110 180 240 310
405]'; % </font>將<font FACE="Times New Roman"> rpm=3000 </font>的溫度輸入</font>
<br>
<br>
<font COLOR="#FF0000"><font FACE="Times New Roman">>> d2(:,4)=[4000 176 220 349 450
503]'; % </font>將<font FACE="Times New Roman"> rpm=4000 </font>的溫度輸入</font>
<br>
<br>
<font COLOR="#FF0000" FACE="Times New Roman">>> t=d2(2:6,1); %</font><font COLOR="#FF0000">選擇做內插的時間</font><br>
<font COLOR="#FF0000"><font FACE="Times New Roman">>> rpm=d2(1,2:4); % </font>選擇做內插的<font FACE="Times New Roman"> rpm</font></font> <br>
<br>
<font COLOR="#FF0000" FACE="Times New Roman">>> temp=d2(2:6,2:4); % </font><font COLOR="#FF0000">選擇做內插的溫度</font><br>
<font COLOR="#FF0000"><font FACE="Times New Roman">>>
temp_i=interp2(rpm,t,temp,2500,2.6) % </font>以線形內插決定<font FACE="Times New Roman"> rpm=2500,t=2.6 </font>的溫度</font> <br>
<br>
<font COLOR="#FF0000" FACE="Times New Roman">temp_i =</font> <br>
<br>
<font COLOR="#FF0000" FACE="Times New Roman">140.4000</font> </p>
<hr>
<a HREF="ch7_1_1.htm" tppabs="http://webclass.ncu.edu.tw/~junwu/ch7_1_1.htm">
<p><img SRC="../img3/lastpage.gif" tppabs="http://webclass.ncu.edu.tw/~junwu/lastpage.gif" BORDER="0" WIDTH="42" HEIGHT="42"></a> <a HREF="ch7_1_3.htm" tppabs="http://webclass.ncu.edu.tw/~junwu/ch7_1_3.htm"><img SRC="../img3/nextpage.gif" tppabs="http://webclass.ncu.edu.tw/~junwu/nextpage.gif" HSPACE="10" BORDER="0" WIDTH="42" HEIGHT="42"></a> <a HREF="../index.html" tppabs="http://webclass.ncu.edu.tw/~junwu/index.html"><img SRC="../img3/outline.gif" tppabs="http://webclass.ncu.edu.tw/~junwu/outline.gif" HSPACE="6" BORDER="0" WIDTH="42" HEIGHT="42"></a> </p>
<p><font color="#FF00FF">上一頁 下一頁 講義大綱</font></p>
</body>
</html>
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -