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<a name="Inline-Functions"></a>
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<p>
Previous: <a href="Anonymous-Functions.html#Anonymous-Functions" accesskey="p" rel="prev">Anonymous Functions</a>, Up: <a href="Function-Handles-Anonymous-Functions-Inline-Functions.html#Function-Handles-Anonymous-Functions-Inline-Functions" accesskey="u" rel="up">Function Handles Anonymous Functions Inline Functions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Inline-Functions-1"></a>
<h4 class="subsection">11.11.3 Inline Functions</h4>
<p>An inline function is created from a string containing the function
body using the <code>inline</code> function. The following code defines the
function <em>f(x) = x^2 + 2</em>.
</p>
<div class="example">
<pre class="example">f = inline ("x^2 + 2");
</pre></div>
<p>After this it is possible to evaluate <em>f</em> at any <em>x</em> by
writing <code>f(x)</code>.
</p>
<p><strong>Caution</strong>: <small>MATLAB</small> has begun the process of deprecating inline
functions. At some point in the future support will be dropped and eventually
Octave will follow <small>MATLAB</small> and also remove inline functions. Use anonymous
functions in all new code.
</p>
<a name="XREFinline"></a><dl>
<dt><a name="index-inline"></a><em></em> <strong>inline</strong> <em>(<var>str</var>)</em></dt>
<dt><a name="index-inline-1"></a><em></em> <strong>inline</strong> <em>(<var>str</var>, <var>arg1</var>, …)</em></dt>
<dt><a name="index-inline-2"></a><em></em> <strong>inline</strong> <em>(<var>str</var>, <var>n</var>)</em></dt>
<dd><p>Create an inline function from the character string <var>str</var>.
</p>
<p>If called with a single argument, the arguments of the generated function
are extracted from the function itself. The generated function arguments
will then be in alphabetical order. It should be noted that i and j are
ignored as arguments due to the ambiguity between their use as a variable or
their use as an built-in constant. All arguments followed by a parenthesis
are considered to be functions. If no arguments are found, a function
taking a single argument named <code>x</code> will be created.
</p>
<p>If the second and subsequent arguments are character strings, they are the
names of the arguments of the function.
</p>
<p>If the second argument is an integer <var>n</var>, the arguments are
<code>"x"</code>, <code>"P1"</code>, …, <code>"P<var>N</var>"</code>.
</p>
<p>Programming Note: The use of <code>inline</code> is discouraged and it may be
removed from a future version of Octave. The preferred way to create
functions from strings is through the use of anonymous functions
(see <a href="Anonymous-Functions.html#Anonymous-Functions">Anonymous Functions</a>) or <code>str2func</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFargnames">argnames</a>, <a href="#XREFformula">formula</a>, <a href="Basic-Vectorization.html#XREFvectorize">vectorize</a>, <a href="Function-Handles.html#XREFstr2func">str2func</a>.
</p></dd></dl>
<a name="XREFargnames"></a><dl>
<dt><a name="index-argnames"></a><em></em> <strong>argnames</strong> <em>(<var>fun</var>)</em></dt>
<dd><p>Return a cell array of character strings containing the names of the
arguments of the inline function <var>fun</var>.
</p>
<p><strong>See also:</strong> <a href="#XREFinline">inline</a>, <a href="#XREFformula">formula</a>, <a href="Basic-Vectorization.html#XREFvectorize">vectorize</a>.
</p></dd></dl>
<a name="XREFformula"></a><dl>
<dt><a name="index-formula"></a><em></em> <strong>formula</strong> <em>(<var>fun</var>)</em></dt>
<dd><p>Return a character string representing the inline function <var>fun</var>.
</p>
<p>Note that <code>char (<var>fun</var>)</code> is equivalent to
<code>formula (<var>fun</var>)</code>.
</p>
<p><strong>See also:</strong> <a href="Concatenating-Strings.html#XREFchar">char</a>, <a href="#XREFargnames">argnames</a>, <a href="#XREFinline">inline</a>, <a href="Basic-Vectorization.html#XREFvectorize">vectorize</a>.
</p></dd></dl>
<a name="XREFsymvar"></a><dl>
<dt><a name="index-symvar"></a><em><var>vars</var> =</em> <strong>symvar</strong> <em>(<var>str</var>)</em></dt>
<dd><p>Identify the symbolic variable names in the string <var>str</var>.
</p>
<p>Common constant names such as <code>i</code>, <code>j</code>, <code>pi</code>, <code>Inf</code> and
Octave functions such as <code>sin</code> or <code>plot</code> are ignored.
</p>
<p>Any names identified are returned in a cell array of strings. The array is
empty if no variables were found.
</p>
<p>Example:
</p>
<div class="example">
<pre class="example">symvar ("x^2 + y^2 == 4")
⇒ {
[1,1] = x
[2,1] = y
}
</pre></div>
</dd></dl>
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Previous: <a href="Anonymous-Functions.html#Anonymous-Functions" accesskey="p" rel="prev">Anonymous Functions</a>, Up: <a href="Function-Handles-Anonymous-Functions-Inline-Functions.html#Function-Handles-Anonymous-Functions-Inline-Functions" accesskey="u" rel="up">Function Handles Anonymous Functions Inline Functions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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