<html lang="en"> <head> <title>Creating Diagonal Matrices - 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="Basic-Usage.html#Basic-Usage" title="Basic Usage"> <link rel="next" href="Creating-Permutation-Matrices.html#Creating-Permutation-Matrices" title="Creating Permutation Matrices"> <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="Creating-Diagonal-Matrices"></a> <p> Next: <a rel="next" accesskey="n" href="Creating-Permutation-Matrices.html#Creating-Permutation-Matrices">Creating Permutation Matrices</a>, Up: <a rel="up" accesskey="u" href="Basic-Usage.html#Basic-Usage">Basic Usage</a> <hr> </div> <h4 class="subsection">20.1.1 Creating Diagonal Matrices</h4> <p>The most common and easiest way to create a diagonal matrix is using the built-in function <dfn>diag</dfn>. 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>Diagonal matrix with unit elements can be created using <dfn>eye</dfn>. Some other built-in functions can also return diagonal matrices. Examples include <dfn>balance</dfn> or <dfn>inv</dfn>. <p>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 </pre> </body></html>