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Previous: <a rel="previous" accesskey="p" href="Manipulating-Structures.html#Manipulating-Structures">Manipulating Structures</a>,
Up: <a rel="up" accesskey="u" href="Data-Structures.html#Data-Structures">Data Structures</a>
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<h4 class="subsection">6.1.5 Processing Data in Structures</h4>
<p>The simplest way to process data in a structure is within a <code>for</code>
loop (see <a href="Looping-Over-Structure-Elements.html#Looping-Over-Structure-Elements">Looping Over Structure Elements</a>). A similar effect can be
achieved with the <code>structfun</code> function, where a user defined
function is applied to each field of the structure.
<!-- ./general/structfun.m -->
<p><a name="doc_002dstructfun"></a>
<div class="defun">
— Function File: <b>structfun</b> (<var>func, s</var>)<var><a name="index-structfun-382"></a></var><br>
— Function File: [<var>a</var>, <var>b</var>] = <b>structfun</b> (<var><small class="dots">...</small></var>)<var><a name="index-structfun-383"></a></var><br>
— Function File: <b>structfun</b> (<var><small class="dots">...</small>, "ErrorHandler", errfunc</var>)<var><a name="index-structfun-384"></a></var><br>
— Function File: <b>structfun</b> (<var><small class="dots">...</small>, "UniformOutput", val</var>)<var><a name="index-structfun-385"></a></var><br>
<blockquote>
<p>Evaluate the function named <var>name</var> on the fields of the structure
<var>s</var>. The fields of <var>s</var> are passed to the function <var>func</var>
individually.
<p><code>structfun</code> accepts an arbitrary function <var>func</var> in the form of
an inline function, function handle, or the name of a function (in a
character string). In the case of a character string argument, the
function must accept a single argument named <var>x</var>, and it must return
a string value. If the function returns more than one argument, they are
returned as separate output variables.
<p>If the parameter "UniformOutput" is set to true (the default), then the function
must return a single element which will be concatenated into the
return value. If "UniformOutput" is false, the outputs placed in a structure
with the same fieldnames as the input structure.
<pre class="example"> s.name1 = "John Smith";
s.name2 = "Jill Jones";
structfun (@(x) regexp (x, '(\w+)$', "matches"){1}, s,
"UniformOutput", false)
</pre>
<p>Given the parameter "ErrorHandler", then <var>errfunc</var> defines a function to
call in case <var>func</var> generates an error. The form of the function is
<pre class="example"> function [...] = errfunc (<var>se</var>, ...)
</pre>
<p>where there is an additional input argument to <var>errfunc</var> relative to
<var>func</var>, given by <var>se</var>. This is a structure with the elements
"identifier", "message" and "index", giving respectively the error
identifier, the error message, and the index into the input arguments
of the element that caused the error.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dcellfun.html#doc_002dcellfun">cellfun</a>, <a href="doc_002darrayfun.html#doc_002darrayfun">arrayfun</a>.
</p></blockquote></div>
<p>Alternatively, to process the data in a structure, the structure might
be converted to another type of container before being treated.
<!-- ov-cell.cc -->
<p><a name="doc_002dstruct2cell"></a>
<div class="defun">
— Built-in Function: <b>struct2cell</b> (<var>S</var>)<var><a name="index-struct2cell-386"></a></var><br>
<blockquote><p>Create a new cell array from the objects stored in the struct object.
If <var>f</var> is the number of fields in the structure, the resulting
cell array will have a dimension vector corresponding to
<code>[</code><var>F</var><code> size(</code><var>S</var><code>)]</code>.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dcell2struct.html#doc_002dcell2struct">cell2struct</a>, <a href="doc_002dfieldnames.html#doc_002dfieldnames">fieldnames</a>.
</p></blockquote></div>
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