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Next: <a href="Creating-Permutation-Matrices.html#Creating-Permutation-Matrices" accesskey="n" rel="next">Creating Permutation Matrices</a>, Up: <a href="Basic-Usage.html#Basic-Usage" accesskey="u" rel="up">Basic Usage</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Creating-Diagonal-Matrices-1"></a>
<h4 class="subsection">21.1.1 Creating Diagonal Matrices</h4>
<p>The most common and easiest way to create a diagonal matrix is using the
built-in function <em>diag</em>. The expression <code>diag (v)</code>, with <var>v</var> a
vector, will create a square diagonal matrix with elements on the main diagonal
given by the elements of <var>v</var>, and size equal to the length of <var>v</var>.
<code>diag (v, m, n)</code> can be used to construct a rectangular diagonal matrix.
The result of these expressions will be a special diagonal matrix object, rather
than a general matrix object.
</p>
<p>Diagonal matrix with unit elements can be created using <em>eye</em>.
Some other built-in functions can also return diagonal matrices. Examples
include
<em>balance</em> or <em>inv</em>.
</p>
<p>Example:
</p>
<div class="example">
<pre class="example"> diag (1:4)
⇒
Diagonal Matrix
1 0 0 0
0 2 0 0
0 0 3 0
0 0 0 4
diag (1:3,5,3)
⇒
Diagonal Matrix
1 0 0
0 2 0
0 0 3
0 0 0
0 0 0
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