Latex common summary (2): input matrix (input matrix, diagonal matrix, equations, etc.)

Latex How to input various matrices ：

\usepackage{
    amsmath,amssymb,amsfonts}
1. Direct use matrix、pmatrix、bmatrix、Bmatrix perhaps vmatrix

2. The second method  array

3. Insert equations 

The first method

（1） Direct use matrix

\begin{
    equation*}
\begin{
    matrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    matrix}
\end{
    equation*}

Our output is :

（2） Direct use pmatrix

\begin{
    equation*}
\begin{
    pmatrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    pmatrix}
\end{
    equation*}

Our output is :

（3） Direct use bmatrix

\begin{
    equation*}
\begin{
    bmatrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    bmatrix}
\end{
    equation*}

Our output is :

（4） Direct use Bmatrix

\begin{
    equation*}
\begin{
    Bmatrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    Bmatrix}
\end{
    equation*}

Our output is :

（5） Direct use vmatrix

\begin{
    equation*}
\begin{
    vmatrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    vmatrix}
\end{
    equation*}

Our output is :

（6） Direct use Vmatrix

\begin{
    equation*}
\begin{
    Vmatrix} 
1 & 0 & 0\\ 
0 & 1 & 0\\
0 & 0 &1 
\end{
    Vmatrix}
\end{
    equation*}

Our output is :

Let's summarize :

\begin{
    equation*}
	\begin{
    gathered}
	\begin{
    matrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    matrix}
	\quad
	\begin{
    pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    pmatrix}
	\quad
	\begin{
    bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    bmatrix}
	\quad
	\begin{
    Bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    Bmatrix}
	\quad
	\begin{
    vmatrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    vmatrix}
	\quad
	\begin{
    Vmatrix} 1 & 0 & 0 \\ 0 & 1 & 0\\ 0 & 0 &1 \end{
    Vmatrix}
	\end{
    gathered}
\end{
    equation*}

Our output is :

（7） The most commonly used matrix insertion

\begin{
    equation*}
	\begin{
    bmatrix}
	 a_{
    11} & a_{
    12} & a_{
    13} \\
	a_{
    21} & a_{
    22} & a_{
    23} \\
	a_{
    31} & a_{
    32} & a_{
    33}
	 \end{
    bmatrix}
\end{
    equation*}

Our output is :

（8） Diagonal matrix insertion ：

\begin{
    equation*}
	\begin{
    bmatrix}
	 a_{
    11} &   & &  \\
	  & a_{
    22} &  & \\
	  &   & a_{
    33}&\\
	  &   &  &a_{
    44}
	 \end{
    bmatrix}
\end{
    equation*}

（9） Writing of complex matrix

\begin{
    equation*}
	\begin{
    bmatrix} 
	a1 & a2 & \cdots & an\\
   b1 & b2 & \cdots & bn\\
   \vdots & \vdots &\ddots & \vdots\\
   m1 & m2 & \cdots & mn
	\end{
    bmatrix}
\end{
    equation*}

Our output is :

The second method array

\begin{
    equation*}
\left[
\begin{
    array}{
    ccc}
a_{
    11} & a_{
    12} & a_{
    13} \\
a_{
    21} & a_{
    22} & a_{
    23} \\
a_{
    31} & a_{
    32} & a_{
    33} 
\end{
    array}
\right]        
\end{
    equation*}

Our output is :

Summary of matrix multiplication

\begin{
    equation*}
\left[
\begin{
    array}{
    c}
X \\
\Theta \\
y
\end{
    array}
\right]
=
\left[
\begin{
    array}{
    ccc}
a_{
    11} & a_{
    12} & a_{
    13} \\
a_{
    21} & a_{
    22} & a_{
    23} \\
a_{
    31} & a_{
    32} & a_{
    33}
\end{
    array}
\right]
\left[
\begin{
    array}{
    c}
b_{
    1} \\ 
b_{
    2} \\
b_{
    3}
\end{
    array}
\right]
\end{
    equation*}

Our output is :

Insert equations

\begin{
    equation*}
\left\{
    
\begin{
    array}{
    c}
a_{
    11}x_1+a_{
    12}x_2+\cdots+a_{
    1n}x_n=b_1 \\
a_{
    21}x_1+a_{
    22}x_2+\cdots+a_{
    2n}x_n=b_2 \\
\cdots \\
a_{
    n1}x_1+a_{
    n2}x_2+\cdots+a_{
    nn}x_n=b_n
\end{
    array}
\right.
\end{
    equation*}

Our output is :