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<p>
<a name="Creating-Cell-Arrays"></a>
Next: <a rel="next" accesskey="n" href="Indexing-Cell-Arrays.html#Indexing-Cell-Arrays">Indexing Cell Arrays</a>,
Previous: <a rel="previous" accesskey="p" href="Basic-Usage-of-Cell-Arrays.html#Basic-Usage-of-Cell-Arrays">Basic Usage of Cell Arrays</a>,
Up: <a rel="up" accesskey="u" href="Cell-Arrays.html#Cell-Arrays">Cell Arrays</a>
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<h4 class="subsection">6.2.2 Creating Cell Array</h4>
<p>The introductory example (see <a href="Basic-Usage-of-Cell-Arrays.html#Basic-Usage-of-Cell-Arrays">Basic Usage of Cell Arrays</a>) showed
how to create a cell array containing currently available variables.
In many situations, however, it is useful to create a cell array and
then fill it with data.
<p>The <code>cell</code> function returns a cell array of a given size, containing
empty matrices. This function is similar to the <code>zeros</code>
function for creating new numerical arrays. The following example creates
a 2-by-2 cell array containing empty matrices
<pre class="example"> c = cell(2,2)
c =
{
[1,1] = [](0x0)
[2,1] = [](0x0)
[1,2] = [](0x0)
[2,2] = [](0x0)
}
</pre>
<p>Just like numerical arrays, cell arrays can be multidimensional. The
<code>cell</code> function accepts any number of positive integers to describe
the size of the returned cell array. It is also possible to set the size
of the cell array through a vector of positive integers. In the
following example two cell arrays of equal size are created, and the size
of the first one is displayed
<pre class="example"> c1 = cell(3, 4, 5);
c2 = cell( [3, 4, 5] );
size(c1)
ans =
3 4 5
</pre>
<p class="noindent">As can be seen, the <a href="doc_002dsize.html#doc_002dsize"><code>size</code></a> function also works
for cell arrays. As do other functions describing the size of an
object, such as <a href="doc_002dlength.html#doc_002dlength"><code>length</code></a>, <a href="doc_002dnumel.html#doc_002dnumel"><code>numel</code></a>, <a href="doc_002drows.html#doc_002drows"><code>rows</code></a>, and <a href="doc_002dcolumns.html#doc_002dcolumns"><code>columns</code></a>.
<!-- ov-cell.cc -->
<p><a name="doc_002dcell"></a>
<div class="defun">
— Built-in Function: <b>cell</b> (<var>x</var>)<var><a name="index-cell-390"></a></var><br>
— Built-in Function: <b>cell</b> (<var>n, m</var>)<var><a name="index-cell-391"></a></var><br>
<blockquote><p>Create a new cell array object. If invoked with a single scalar
argument, <code>cell</code> returns a square cell array with the dimension
specified. If you supply two scalar arguments, <code>cell</code> takes
them to be the number of rows and columns. If given a vector with two
elements, <code>cell</code> uses the values of the elements as the number of
rows and columns, respectively.
</p></blockquote></div>
<p>As an alternative to creating empty cell arrays, and then filling them, it
is possible to convert numerical arrays into cell arrays using the
<code>num2cell</code> and <code>mat2cell</code> functions.
<!-- ./DLD-FUNCTIONS/cellfun.cc -->
<p><a name="doc_002dnum2cell"></a>
<div class="defun">
— Loadable Function: <var>c</var> = <b>num2cell</b> (<var>m</var>)<var><a name="index-num2cell-392"></a></var><br>
— Loadable Function: <var>c</var> = <b>num2cell</b> (<var>m, dim</var>)<var><a name="index-num2cell-393"></a></var><br>
<blockquote><p>Convert the matrix <var>m</var> to a cell array. If <var>dim</var> is defined, the
value <var>c</var> is of dimension 1 in this dimension and the elements of
<var>m</var> are placed in slices in <var>c</var>.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dmat2cell.html#doc_002dmat2cell">mat2cell</a>.
</p></blockquote></div>
<!-- ./DLD-FUNCTIONS/cellfun.cc -->
<p><a name="doc_002dmat2cell"></a>
<div class="defun">
— Loadable Function: <var>b</var> = <b>mat2cell</b> (<var>a, m, n</var>)<var><a name="index-mat2cell-394"></a></var><br>
— Loadable Function: <var>b</var> = <b>mat2cell</b> (<var>a, d1, d2, <small class="dots">...</small></var>)<var><a name="index-mat2cell-395"></a></var><br>
— Loadable Function: <var>b</var> = <b>mat2cell</b> (<var>a, r</var>)<var><a name="index-mat2cell-396"></a></var><br>
<blockquote><p>Convert the matrix <var>a</var> to a cell array. If <var>a</var> is 2-D, then
it is required that <code>sum (</code><var>m</var><code>) == size (</code><var>a</var><code>, 1)</code> and
<code>sum (</code><var>n</var><code>) == size (</code><var>a</var><code>, 2)</code>. Similarly, if <var>a</var> is
a multi-dimensional and the number of dimensional arguments is equal
to the dimensions of <var>a</var>, then it is required that <code>sum (</code><var>di</var><code>)
== size (</code><var>a</var><code>, i)</code>.
<p>Given a single dimensional argument <var>r</var>, the other dimensional
arguments are assumed to equal <code>size (</code><var>a</var><code>,</code><var>i</var><code>)</code>.
<p>An example of the use of mat2cell is
<pre class="example"> mat2cell (reshape(1:16,4,4),[3,1],[3,1])
{
[1,1] =
1 5 9
2 6 10
3 7 11
[2,1] =
4 8 12
[1,2] =
13
14
15
[2,2] = 16
}
</pre>
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dnum2cell.html#doc_002dnum2cell">num2cell</a>, <a href="doc_002dcell2mat.html#doc_002dcell2mat">cell2mat</a>.
</p></blockquote></div>
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