LaTeX

1. 括号

• fraction：$\frac{a}{b}$，$\frac{a}{b}$
• parenthesis：$\left(\frac{a}{b}\right)$，$\left( \frac{a}{b} \right)$
• bracket：$\left[\frac{a}{b}\right]$，$\left[ \frac{a}{b} \right]$
• brace：$\left\{\frac{a}{b}\right\}$，$\left\{ \frac{a}{b} \right\}$
• absolute value：$\left|\frac{a}{b}\right|$，$\left| \frac{a}{b} \right|$
• angle bracket：$⟨\frac{a}{b}⟩$，$\left \langle \frac{a}{b} \right \rangle$
• norm（范数）：$\Vert \frac{a}{b}\Vert$，$\left \| \frac{a}{b} \right \|$
• floor function（取整函数）：$\lfloor \frac{a}{b}\rfloor$，$\left \lfloor \frac{a}{b} \right \rfloor$
• ceiling function（取顶函数）：$\lceil \frac{c}{d}\rceil$，$\left \lceil \frac{c}{d} \right \rceil$
• slashes and backslashes：$/\frac{a}{b}\backslash$，$\left / \frac{a}{b} \right \backslash$
• arrows：
  • $\uparrow \frac{a}{b}\downarrow$，$\left \uparrow \frac{a}{b} \right \downarrow$
  • $\Uparrow \frac{a}{b}\Downarrow$，$\left \Uparrow \frac{a}{b} \right \Downarrow$
  • $\updownarrow \frac{a}{b}\Updownarrow$，$\left \updownarrow \frac{a}{b} \right \Updownarrow$
• mixed brackets：$\left[0,1\right)⟨\psi |$，$\left [ 0,1 \right )\left \langle \psi \right |$
• single left parenthesis：$\{\frac{a}{b}$，$\left \{ \frac{a}{b} \right .$
• single right parenthesis：$\frac{a}{b}\}$，$\left . \frac{a}{b} \right \}$
• size of parenthesis（\big < \Big < \bigg < \Bigg）：$\left(\right[\{⟨\left|\Vert x\Vert \right|⟩\}\left]\right)$，$\Bigg ( \bigg [ \Big \{ \big \langle \left | \| x \| \right | \big \rangle \Big \} \bigg ] \Bigg )$

2. 上下标

• superscript：$a^{b+c}$，$a^{b+c}$
• subscript：$a_{b+c}$，$a_{b+c}$
• note：$a_m^n$, $a_m^n$, ${a^n}_m$, ${a_m}^n$，$a^{n}_{m}$, $a_{m}^{n}$, ${a^{n}}_{m}$, ${a_{m}}^{n}$
• derivative：$a=a^{\prime }$, $b_0^{\prime }=b_{0^{\prime }}$, $c^{\prime 2}=(c^{\prime }{)}^2$，$a=a'$, $b_{0}'=b_{0'}$, $c'^{2}=(c')^{2}$
• others：$\stackrel{\ast }{X}$, $\underset{†}{A}$, $\underset{†}{\stackrel{\ast }{X}}$，$\overset{*}{X}$, $\underset{\dag}{A}$, $\underset{\dag}{\overset{*}{X}}$

3. 矩阵

$$\begin{array}{c}\begin{array}{cc}0& 1\\ 1& 0\end{array}\left(\begin{array}{cc}0& -i\\ i& 0\end{array}\right)\left[\begin{array}{cc}0& -1\\ 1& 0\end{array}\right]\left\{\begin{array}{cc}1& 0\\ 0& -1\end{array}\right\}\left|\begin{array}{cc}a& b\\ c& d\end{array}\right|\Vert \begin{array}{cc}i& 0\\ 0& -i\end{array}\Vert \end{array}$$

$$
\begin{gathered}
\begin{matrix} 0 & 1 \\ 1 & 0 \end{matrix}
\quad
\begin{pmatrix} 0 & -i \\ i & 0 \end{pmatrix}
\quad
\begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}
\quad
\begin{Bmatrix} 1 & 0 \\ 0 & -1 \end{Bmatrix}
\quad
\begin{vmatrix} a & b \\ c & d \end{vmatrix}
\quad
\begin{Vmatrix} i & 0 \\ 0 & -i \end{Vmatrix}
\end{gathered}
$$

4. 方程组

$$\{\begin{array}{lr}x=\frac{3\pi }{2}(1+2t)\cos (\frac{3\pi }{2}(1+2t)),& \\ y=s,& 0\le s\le L,|t|\le 1.\\ z=\frac{3\pi }{2}(1+2t)\sin (\frac{3\pi }{2}(1+2t)),& \end{array}$$

$$
\left\{  
             \begin{array}{lr}  
             x=\dfrac{3\pi}{2}(1+2t)\cos(\dfrac{3\pi}{2}(1+2t)), &  \\  
             y=s, & 0\leq s\leq L,|t|\leq1.\\  
             z=\dfrac{3\pi}{2}(1+2t)\sin(\dfrac{3\pi}{2}(1+2t)), &    
             \end{array}  
\right.
$$

$$\{\begin{array}{rc}I{F}_k({\hat{t}}_{k,m})=I{F}_m({\hat{t}}_{k,m}),& \\ I{F}_k({\hat{t}}_{k,m})\pm h=I{F}_m({\hat{t}}_{k,m})\pm h,& \\ \left|I{F}_k^{\prime }({\hat{t}}_{k,m}-I{F}_m^{\prime }({\hat{t}}_{k,m}\right|\ge d,& \end{array}$$

$$
\left\{  
\begin{array}{rcl}
    IF_{k}(\hat{t}_{k,m})=IF_{m}(\hat{t}_{k,m}), & \\
    IF_{k}(\hat{t}_{k,m}) \pm h= IF_{m}(\hat{t}_{k,m}) \pm h  , &\\
    \left |IF'_{k}(\hat{t}_{k,m} - IF'_{m}(\hat{t}_{k,m} \right |\geq d , &   
\end{array}
\right.  
$$ 

5. 分段函数

$$f(x)=\{\begin{array}{rlr}x& =& \cos (t)\\ y& =& \sin (t)\\ z& =& \frac{x}{y}\end{array}$$

$$ 
f(x)=\left\{
\begin{aligned}
x & = & \cos(t) \\
y & = & \sin(t) \\
z & = & \frac xy
\end{aligned}
\right.
$$

$$F^{HLLC}=\{\begin{array}{rcl}{F}_L& & 0<S_L\\ F_L^{\ast }& & S_L\le 0<S_M\\ F_R^{\ast }& & S_M\le 0<S_R\\ F_R& & S_R\le 0\end{array}$$

$$ 
F^{HLLC}=\left\{
\begin{array}{rcl}
F_L       &      & {0      <      S_L}\\
F^*_L     &      & {S_L \leq 0 < S_M}\\
F^*_R     &      & {S_M \leq 0 < S_R}\\
F_R       &      & {S_R \leq 0}
\end{array} \right. 
$$

$$f(x)=\{\begin{array}{ll}0& \text{x=0}\\ 1& \text{x!=0}\end{array}$$

$$
f(x)=
\begin{cases}
0& \text{x=0}\\
1& \text{x!=0}
\end{cases}
$$

6. 其他

• space：$ab$，\quad
• $90^{\circ }$，$90^{\circ}$
• infinite：$\infty$，$\infty$
• sigma：${\sum }_{i=1}^n{a}_i$，$\sum_{i=1}^{n}a_{i}$
• capital pi：${\prod }_{i=1}^n{b}_i$，$\prod_{i=1}^{n}b_{i}$
• definite integral：${\int }_a^{b}f(x)$，$\int_{a}^{b}f(x)$
• limit：${\lim }_{n\to \infty }{a}_n$，$\lim_{n\rightarrow\infty}a_{n}$

原文链接：https://qwert.blog.csdn.net/article/details/105898707