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Next: <a rel="next" accesskey="n" href="Anonymous-Functions.html#Anonymous-Functions">Anonymous Functions</a>,
Up: <a rel="up" accesskey="u" href="Function-Handles-Inline-Functions-and-Anonymous-Functions.html#Function-Handles-Inline-Functions-and-Anonymous-Functions">Function Handles Inline Functions and Anonymous Functions</a>
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<h4 class="subsection">11.10.1 Function Handles</h4>
<p>A function handle is a pointer to another function and is defined with
the syntax
<pre class="example"> @<var>function-name</var>
</pre>
<p class="noindent">For example,
<pre class="example"> f = @sin;
</pre>
<p class="noindent">creates a function handle called <code>f</code> that refers to the
function <code>sin</code>.
<p>Function handles are used to call other functions indirectly, or to pass
a function as an argument to another function like <code>quad</code> or
<code>fsolve</code>. For example:
<pre class="example"> f = @sin;
quad (f, 0, pi)
⇒ 2
</pre>
<p>You may use <code>feval</code> to call a function using function handle, or
simply write the name of the function handle followed by an argument
list. If there are no arguments, you must use an empty argument list
‘<samp><span class="samp">()</span></samp>’. For example:
<pre class="example"> f = @sin;
feval (f, pi/4)
⇒ 0.70711
f (pi/4)
⇒ 0.70711
</pre>
<!-- is_function_handle src/ov-fcn-handle.cc -->
<p><a name="doc_002dis_005ffunction_005fhandle"></a>
<div class="defun">
— Built-in Function: <b>is_function_handle</b> (<var>x</var>)<var><a name="index-is_005ffunction_005fhandle-790"></a></var><br>
<blockquote><p>Return true if <var>x</var> is a function handle.
<!-- Texinfo @sp should work but in practice produces ugly results for HTML. -->
<!-- A simple blank line produces the correct behavior. -->
<!-- @sp 1 -->
<p class="noindent"><strong>See also:</strong> <a href="doc_002disa.html#doc_002disa">isa</a>, <a href="doc_002dtypeinfo.html#doc_002dtypeinfo">typeinfo</a>, <a href="doc_002dclass.html#doc_002dclass">class</a>.
</p></blockquote></div>
<!-- functions src/ov-fcn-handle.cc -->
<p><a name="doc_002dfunctions"></a>
<div class="defun">
— Built-in Function: <b>functions</b> (<var>fcn_handle</var>)<var><a name="index-functions-791"></a></var><br>
<blockquote><p>Return a struct containing information about the function handle
<var>fcn_handle</var>.
</p></blockquote></div>
<!-- func2str src/ov-fcn-handle.cc -->
<p><a name="doc_002dfunc2str"></a>
<div class="defun">
— Built-in Function: <b>func2str</b> (<var>fcn_handle</var>)<var><a name="index-func2str-792"></a></var><br>
<blockquote><p>Return a string containing the name of the function referenced by
the function handle <var>fcn_handle</var>.
</p></blockquote></div>
<!-- str2func src/ov-fcn-handle.cc -->
<p><a name="doc_002dstr2func"></a>
<div class="defun">
— Built-in Function: <b>str2func</b> (<var>fcn_name</var>)<var><a name="index-str2func-793"></a></var><br>
— Built-in Function: <b>str2func</b> (<var>fcn_name, "global"</var>)<var><a name="index-str2func-794"></a></var><br>
<blockquote><p>Return a function handle constructed from the string <var>fcn_name</var>.
If the optional "global" argument is passed, locally visible functions
are ignored in the lookup.
</p></blockquote></div>
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