my matrix doesnt fit the page

Use symbols:

\documentclass[11pt]{article}
\usepackage{amsmath}

\DeclareMathOperator{\diag}{diag}

\begin{document}

\begin{equation*}
[a_{ii}]=[\phi]^T[A][\phi] = \diag(\delta_1,\delta_2,\delta_3,\delta_4,\delta_5,\delta_6)
\end{equation*}
where
\begin{equation*}
\begin{aligned}
\delta_1 &= -0.0829 + 0.2686i, \\
\delta_2 &= -0.0829 - 0.2686i, \\
\delta_3 &= -0.2040 + 2.5845i, \\
\delta_4 &= -0.2040 - 2.5845i, \\
\delta_5 &= 3.2154, \\
\delta_6 &= -3.0137
\end{aligned}
\end{equation*}

\end{document}

enter image description here

You can also type in the full matrix, but the “diag” notation is clearer, in my opinion.


Yet another possibility is negative space as column separator.

\documentclass[11pt]{article}
\usepackage{amsmath}
\begin{document}
\newcommand\shrink{\hspace{-3em}}
\begin{align*}
[a_{ii}]&=[\phi]^T[A][\phi]\\
&=
\left[\begin{array}{@{}[email protected]{\shrink}[email protected]{\shrink}[email protected]{\shrink}[email protected]{}[email protected]{\hspace{-0.5em}}[email protected]{}}
-0.0829 + 0.2686i&0&0&0&0&0\\
0&-0.0829 - 0.2686i&0&0&0&0\\
0&0&-0.2040 + 2.5845i&0&0&0\\
0&0&0&-0.2040 - 2.5845i&0&0\\
0&0&0&0&3.2154&0\\
0&0&0&0&0&-3.0137
\end{array}
\right]
\end{align*}
\end{document}

enter image description here


Yet another option, change the textsize:

\documentclass[11pt]{article}
\usepackage[fleqn]{amsmath}

\begin{document}

\begin{tiny}

{\setlength{\mathindent}{0cm}
\begin{equation*}
[a_{ii}]=[\phi]^T[A][\phi]=\begin{bmatrix}
-0.0829 + 0.2686i&0&0&0&0&0\\
0&-0.0829 - 0.2686i&0&0&0&0\\
0&0&-0.2040 + 2.5845i&0&0&0\\
0&0&0&-0.2040 - 2.5845i&0&0\\
0&0&0&0&3.2154&0\\
0&0&0&0&0&-3.0137
\end{bmatrix}
\end{equation*}
}

\end{tiny}

\end{document}

Tags:

Matrices