>Sigma[1, 1] = 1.0;</code></pre>
<p>sets the value in the first column of the first row of <code>Sigma</code> to one.</p>
<p>Assignments to subcomponents of larger multi-variate data structures
are supported by Stan. For example, <code>a</code> is an array of type
<code>real[ , ]</code> and <code>b</code> is an array of type <code>real[]</code>, then
the following two statements are both well-formed.</p>
<pre class="stan"><code>a[3] = b;
b = a[4];</code></pre>
<p>Similarly, if <code>x</code> is a variable d