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<h2 class="titName SG_txta" id="t_7575087b01019jzz"><strong style="font-size:14px;line-height:1.5;"><span lang="en-us">Matlab</span></strong><strong style="font-size:14px;line-height:1.5;">自定义函数的六种方法</strong></h2>
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<p><span lang="en-us">n1、函数文件<span lang="en-us">+调用函数（命令）文件：需单独定义一个自定义函数的<span lang="en-us">M文件；</span></span></span></p>
<p><span lang="en-us">n2、函数文件<span lang="en-us">+子函数：定义一个具有多个自定义函数的<span lang="en-us">M文件；</span></span></span></p>
<p><span lang="en-us">n3、<span lang="en-us">Inline:无需<span lang="en-us">M文件，直接定义；</span></span></span></p>
<p><span lang="en-us">n4、匿名函数；</span></p>
<p><span lang="en-us">n5、<span lang="en-us">Syms+subs：无需<span lang="en-us">M文件，直接定义；</span></span></span></p>
<p><span lang="en-us">n6、字符串<span lang="en-us">+subs：无需<span lang="en-us">M文件，直接定义。</span></span></span></p>
<p><span lang="en-us">------------</span></p>
<p><strong><span lang="en-us">1</span></strong><strong>、函数文件</strong><strong><span lang="en-us">+</span></strong><strong>调用函数文件：定义多个</strong><strong><span lang="en-us">M</span></strong><strong>文件</strong></p>
<p><span lang="en-us">% 调用函数文件<span lang="en-us">:myfile.m</span></span></p>
<p><span lang="en-us">clear</span></p>
<p><span lang="en-us">clc</span></p>
<p><span lang="en-us">for t=1:10</span></p>
<p><span lang="en-us">y=mylfg(t);</span></p>
<p><span lang="en-us">fprintf(‘M^(1/3)=%6.4f\n’,t,y);</span></p>
<p><span lang="en-us">end</span></p>
<p><span lang="en-us">%自定义函数文件<span lang="en-us">: mylfg.m</span></span></p>
<p><span lang="en-us">function y=mylfg(x) %注意：函数名（<span lang="en-us">mylfg）必须与文件名（<span lang="en-us">mylfg.m）一致</span></span></span></p>
<p><span lang="en-us">Y=x^(1/3);</span></p>
<p><strong>注：</strong>这种方法要求自定义函数必须单独写一个<span lang="en-us">M文件，不能与调用的命令文件写在同一个<span lang="en-us">M文件中。</span></span></p>
<p><span lang="en-us"> </span></p>
<p><strong><span lang="en-us">2</span></strong><strong>、函数文件</strong><strong><span lang="en-us">+</span></strong><strong>子函数：定义一个具有多个子函数的</strong><strong><span lang="en-us">M</span></strong><strong>文件</strong></p>
<p><span lang="en-us">%命令文件：<span lang="en-us">funtry2.m</span></span></p>
<p><span lang="en-us">function []=funtry2()</span></p>
<p><span lang="en-us">for t=1:10</span></p>
<p><span lang="en-us">y=lfg2(t)</span></p>
<p><span lang="en-us">fprintf(‘M^(1/3)=%6.4f\n’);</span></p>
<p><span lang="en-us">End</span></p>
<p><span lang="en-us">function y=lfg2(x)</span></p>
<p><span lang="en-us">Y= x^(1/3);</span></p>
<p><span lang="en-us">%注：自定义函数文件<span lang="en-us">funtry2.m中可以定义多个子函数<span lang="en-us">function。子函数<span lang="en-us">lfg2只能被主函数和主函数中的其他子函数调用。</span></span></span></span></p>
<p><span lang="en-us"> </span></p>
<pre class="blockcode"><strong>注意：函数定义格式</strong></pre>
<pre class="blockcode">在<span lang="en-us">matlab中应该做成<span lang="en-us">M文件<span lang="en-us">,文件名要和你文件里的<span lang="en-us">function后面的函数名一致，在<span lang="en-us">File新建一个<span lang="en-us">M-file 在<span lang="en-us">M-file里编辑函数，其格式为：</span></span></span></span></span></span></span></pre>
<pre class="blockcode"><span lang="en-us"> </span></pre>
<pre class="blockcode"><span lang="en-us">function [输出实参表<span lang="en-us">]=函数名<span lang="en-us">(输入实参数<span lang="en-us">)</span></span></span></span></pre>
<pre class="blockcode"><span lang="en-us"> 注释部分</span></pre>
<pre class="blockcode"><span lang="en-us"> 函数体语句</span></pre>
<pre class="blockcode"><span lang="en-us"> return语句<span lang="en-us">(可以有可以没有<span lang="en-us">)</span></span></span></pre>
<pre class="blockcode">如果是文件中的子函数，则可以任意取名，也可以在同一个文件中定义多个子函数：</pre>
<pre class="blockcode"><span lang="en-us"> 例：<span lang="en-us"> function [max,min]=mymainfun(x) %主函数</span></span></pre>
<pre class="blockcode"><span lang="en-us"> n=length(x)；</span></pre>
<pre class="blockcode"><span lang="en-us"> max=mysubfun1(x,n)；<span lang="en-us"> </span></span></pre>
<pre class="blockcode"><span lang="en-us"> min=mysubfun2(x)；</span></pre>
<pre class="blockcode"><span lang="en-us"> function r=mysubfun1(x,n) %子函数<span lang="en-us"> |
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