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<a name="Processing-Data-in-Cell-Arrays"></a>
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Previous: <a rel="previous" accesskey="p" href="Cell-Arrays-of-Strings.html#Cell-Arrays-of-Strings">Cell Arrays of Strings</a>,
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Up: <a rel="up" accesskey="u" href="Cell-Arrays.html#Cell-Arrays">Cell Arrays</a>
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<h4 class="subsection">6.2.4 Processing Data in Cell Arrays</h4>
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<p>Data that is stored in a cell array can be processed in several ways
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depending on the actual data. The most simple way to process that data
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is to iterate through it using one or more <code>for</code> loops. The same
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idea can be implemented easier through the use of the <code>cellfun</code>
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function that calls a user specified function on all elements of a cell
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<p><a name="doc_002dcellfun"></a>
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— Loadable Function: <b>cellfun</b> (<var>name, c</var>)<var><a name="index-cellfun-348"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var>"size", c, k</var>)<var><a name="index-cellfun-349"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var>"isclass", c, class</var>)<var><a name="index-cellfun-350"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var>func, c</var>)<var><a name="index-cellfun-351"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var>func, c, d</var>)<var><a name="index-cellfun-352"></a></var><br>
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— Loadable Function: [<var>a</var>, <var>b</var>] = <b>cellfun</b> (<var><small class="dots">...</small></var>)<var><a name="index-cellfun-353"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var><small class="dots">...</small>, 'ErrorHandler', errfunc</var>)<var><a name="index-cellfun-354"></a></var><br>
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— Loadable Function: <b>cellfun</b> (<var><small class="dots">...</small>, 'UniformOutput', val</var>)<var><a name="index-cellfun-355"></a></var><br>
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<p>Evaluate the function named <var>name</var> on the elements of the cell array
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<var>c</var>. Elements in <var>c</var> are passed on to the named function
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individually. The function <var>name</var> can be one of the functions
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<dt><code>isempty</code><dd>Return 1 for empty elements.
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<br><dt><code>islogical</code><dd>Return 1 for logical elements.
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<br><dt><code>isreal</code><dd>Return 1 for real elements.
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<br><dt><code>length</code><dd>Return a vector of the lengths of cell elements.
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<br><dt><code>ndims</code><dd>Return the number of dimensions of each element.
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<br><dt><code>prodofsize</code><dd>Return the product of dimensions of each element.
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<br><dt><code>size</code><dd>Return the size along the <var>k</var>-th dimension.
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<br><dt><code>isclass</code><dd>Return 1 for elements of <var>class</var>.
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<p>Additionally, <code>cellfun</code> accepts an arbitrary function <var>func</var>
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in the form of an inline function, function handle, or the name of a
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function (in a character string). In the case of a character string
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argument, the function must accept a single argument named <var>x</var>, and
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it must return a string value. The function can take one or more arguments,
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with the inputs args given by <var>c</var>, <var>d</var>, etc. Equally the function
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can return one or more output arguments. For example
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<pre class="example"> cellfun (@atan2, {1, 0}, {0, 1})
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ans = [1.57080 0.00000]
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<p>Note that the default output argument is an array of the same size as the
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<p>If the param 'UniformOutput' is set to true (the default), then the function
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must return either a single element which will be concatenated into the
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return value. If 'UniformOutput is false, the outputs are concatenated in
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a cell array. For example
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<pre class="example"> cellfun ("tolower(x)", {"Foo", "Bar", "FooBar"},
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"UniformOutput",false)
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ans = {"foo", "bar", "foobar"}
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<p>Given the parameter 'ErrorHandler', then <var>errfunc</var> defines a function to
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call in case <var>func</var> generates an error. The form of the function is
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<pre class="example"> function [...] = errfunc (<var>s</var>, ...)
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<p>where there is an additional input argument to <var>errfunc</var> relative to
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<var>func</var>, given by <var>s</var>. This is a structure with the elements
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'identifier', 'message' and 'index', giving respectively the error
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identifier, the error message, and the index into the input arguments
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of the element that caused the error. For example
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<pre class="example"> function y = foo (s, x), y = NaN; endfunction
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cellfun (@factorial, {-1,2},'ErrorHandler',@foo)
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<strong>See also:</strong> isempty, islogical, isreal, length, ndims, numel, size, isclass.
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</p></blockquote></div>
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<p>An alternative is to convert the data to a different container, such as
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a matrix or a data structure. Depending on the data this is possible
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using the <code>cell2mat</code> and <code>cell2struct</code> functions.
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<p><a name="doc_002dcell2mat"></a>
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— Function File: <var>m</var> = <b>cell2mat</b> (<var>c</var>)<var><a name="index-cell2mat-356"></a></var><br>
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<blockquote><p>Convert the cell array <var>c</var> into a matrix by concatenating all
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elements of <var>c</var> into a hyperrectangle. Elements of <var>c</var> must
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be numeric, logical or char, and <code>cat</code> must be able to
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concatenate them together.
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<strong>See also:</strong> mat2cell, num2cell.
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</p></blockquote></div>
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<p><a name="doc_002dcell2struct"></a>
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— Built-in Function: <b>cell2struct</b> (<var>cell, fields, dim</var>)<var><a name="index-cell2struct-357"></a></var><br>
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<blockquote><p>Convert <var>cell</var> to a structure. The number of fields in <var>fields</var>
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must match the number of elements in <var>cell</var> along dimension <var>dim</var>,
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that is <code>numel (</code><var>fields</var><code>) == size (</code><var>cell</var><code>, </code><var>dim</var><code>)</code>.
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<pre class="example"> A = cell2struct ({'Peter', 'Hannah', 'Robert';
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{'Name','Height'}, 1);
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