<html lang="en"> <head> <title>Comma Separated Lists Generated from Cell Arrays - Untitled</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Untitled"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Comma-Separated-Lists.html#Comma-Separated-Lists" title="Comma Separated Lists"> <link rel="next" href="Comma-Separated-Lists-Generated-from-Structure-Arrays.html#Comma-Separated-Lists-Generated-from-Structure-Arrays" title="Comma Separated Lists Generated from Structure Arrays"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Comma-Separated-Lists-Generated-from-Cell-Arrays"></a> <p> 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>, Up: <a rel="up" accesskey="u" href="Comma-Separated-Lists.html#Comma-Separated-Lists">Comma Separated Lists</a> <hr> </div> <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> </body></html>