# Multipling matrices over a number of lines

I am currently having a problem with multiplying matrices over a number of lines, my code is as follows:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[a4paper, total={6in, 8in}]{geometry}
\usepackage{bm}
\usepackage{amsmath}

\begin{document}

\begin{align*}
= \min tr \left \{ \begin{bmatrix}
d_1 & 0 & \cdots & 0\\
0 & d_2 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & d_p\\
0 & 0 & \cdots & 0
\end{bmatrix} \left (\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 1\\
0 & 0 & \cdots & 0
\end{bmatrix} - \begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 0\\
0 & 0 & \cdots & 0
\end{bmatrix} \right ) \\
\begin{bmatrix}
d_1 & 0 & \cdots & 0\\
0 & d_2 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & d_p\\
0 & 0 & \cdots & 0
\end{bmatrix}
\left(\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 1\\
0 & 0 & \cdots & 0
\end{bmatrix} - \begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 0\\
0 & 0 & \cdots & 0
\end{bmatrix} \right) \right \}
\end{align*}

\end{document}


Ideally I would want all of them in the same line, but since they are too long, I have to use multiple lines.
It seems like the problem might be with the curly bracket at the end.

I have tried to implement what is suggested here and have also tried using multiline, but have not been successful.

I am fairly new to latex, so apologies if this question has a very simple answer.
Thank you!

• you can not break the line between \left and \right, use \bigl\{ and \bigr\} also please post the example in a form that we can run without guessing the needed preamble and page size. Jun 11 '20 at 16:52
• Thank you @DavidCarlisle I have added the preamble and page size. Jun 11 '20 at 17:44

I guess that this is part of a bigger display. Since all objects have the same height, you can use \right. and \left. to insert “empty delimiters”.

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{align*}
&= \min \operatorname{tr}
\left \{
\begin{bmatrix}
d_1 & 0 & \cdots & 0\\
0 & d_2 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & d_p\\
0 & 0 & \cdots & 0
\end{bmatrix}
\left(
\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 1\\
0 & 0 & \cdots & 0
\end{bmatrix} -
\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 0\\
0 & 0 & \cdots & 0
\end{bmatrix}
\right )
\right.
\\
&\hspace{6em}\left.
\begin{bmatrix}
d_1 & 0 & \cdots & 0\\
0 & d_2 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & d_p\\
0 & 0 & \cdots & 0
\end{bmatrix}
\left(
\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 1\\
0 & 0 & \cdots & 0
\end{bmatrix} -
\begin{bmatrix}
1 & 0 & \cdots & 0\\
0 & 1 & \cdots & 0\\
\vdots  & \vdots & \ddots  & \vdots\\
0 & 0 & 0 & 0\\
0 & 0 & \cdots & 0
\end{bmatrix}
\right)
\right \}
\end{align*}

\end{document}
`

• Thanks a lot @egreg this answers my question, really appreciate it! Jun 11 '20 at 17:53