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Next: <a rel="next" accesskey="n" href="Comma-Separated-Lists-Generated-from-Structure-Arrays.html#Comma-Separated-Lists-Generated-from-Structure-Arrays">Comma Separated Lists Generated from Structure Arrays</a>,
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<h4 class="subsection">6.3.1 Comma Separated Lists Generated from Cell Arrays</h4>
<p>As has been mentioned above (see <a href="Indexing-Cell-Arrays.html#Indexing-Cell-Arrays">Indexing Cell Arrays</a>), elements
of a cell array can be extracted into a comma separated list with the
<code>{</code> and <code>}</code> operators. By surrounding this list with
<code>[</code> and <code>]</code>, it can be concatenated into an array. For example:
<pre class="example"> a = {1, [2, 3], 4, 5, 6};
b = [a{1:4}]
b =
1 2 3 4
</pre>
<p>Similarly, it is possible to create a new cell array containing cell
elements selected with <code>{}</code>. By surrounding the list with
‘<samp><span class="samp">{</span></samp>’ and ‘<samp><span class="samp">}</span></samp>’ a new cell array will be created, as the
following example illustrates:
<pre class="example"> a = {1, rand(2, 2), "three"};
b = { a{ [1, 3] } }
b =
{
[1,1] = 1
[1,2] = three
}
</pre>
<p>Furthermore, cell elements (accessed by <code>{}</code>) can be passed
directly to a function. The list of elements from the cell array will
be passed as an argument list to a given function as if it is called
with the elements as individual arguments. The two calls to
<code>printf</code> in the following example are identical but the latter is
simpler and can handle cell arrays of an arbitrary size:
<pre class="example"> c = {"GNU", "Octave", "is", "Free", "Software"};
printf ("%s ", c{1}, c{2}, c{3}, c{4}, c{5});
-| GNU Octave is Free Software
printf ("%s ", c{:});
-| GNU Octave is Free Software
</pre>
<p>If used on the left-hand side of an assignment, a comma separated list
generated with <code>{}</code> can be assigned to. An example is
<pre class="example"> in{1} = [10, 20, 30, 40, 50, 60, 70, 80, 90];
in{2} = inf;
in{3} = "last";
in{4} = "first";
out = cell (4, 1);
[out{1:3}] = find (in{1 : 3});
[out{4:6}] = find (in{[1, 2, 4]})
out =
{
[1,1] = 1
[2,1] = 9
[3,1] = 90
[4,1] = 1
[3,1] = 1
[4,1] = 10
}
</pre>
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