刚刚写完一些但又“404”了,所以具体内容以后再写,先看看效果:

[coolcode][tex] e^{i \pi} = -1 [/tex][/coolcode]
[tex] e^{i \pi} = -1 [/tex]
[coolcode][tex]\begin{displaymath}\sum_{\substack{0c$}\\b+x & \textrm{in the morning}\\l & \textrm{all day long}\end{array} \right.\end{displaymath}[/tex][/coolcode]
[tex]\begin{displaymath}y = \left\{ \begin{array}{ll}a & \textrm{if $d>c$}\\b+x & \textrm{in the morning}\\l & \textrm{all day long}\end{array} \right.\end{displaymath}[/tex]
[coolcode][tex]\begin{tabular}{|r|l|}\hline7C0 & hexadecimal \\3700 & octal \\ \cline{2-2}11111000000 & binary \\\hline \hline1984 & decimal \\\hline\end{tabular}[/tex][/coolcode]
[tex]\begin{tabular}{|r|l|}\hline7C0 & hexadecimal \\3700 & octal \\ \cline{2-2}11111000000 & binary \\\hline \hline1984 & decimal \\\hline\end{tabular}[/tex]
[coolcode][tex]\begin{displaymath}\mathop{\mathrm{corr}}(X,Y)=\frac{\displaystyle\sum_{i=1}^n(x_i-\overline x)(y_i-\overl

ine y)}{\displaystyle\biggl[\sum_{i=1}^n(x_i-\overline x)^2\sum_{i=1}^n(y_i-\overline y)^2\biggr]^{1/2}}\end{displaymath}[/tex][/coolcode]
[tex]\begin{displaymath}\mathop{\mathrm{corr}}(X,Y)=\frac{\displaystyle\sum_{i=1}^n(x_i-\overline x)(y_i-\overline y)}{\displaystyle\biggl[\sum_{i=1}^n(x_i-\overline x)^2\sum_{i=1}^n(y_i-\overline y)^2\biggr]^{1/2}}\end{displaymath}[/tex]
[coolcode][tex]\setlength{\unitlength}{1mm}\begin{picture}(60,40)\put(30,20){\vector(1,0){30}}\put(30,20){\vector(4,1){20}}\put(30,20){\vector(3,1){25}}\put(30,20){\vector(2,1){30}}\put(30,20){\vector(1,2){10}}\thicklines\put(30,20){\vector(-4,1){30}}\put(30,20){\vector(-1,4){5}}\thinlines\put(30,20){\vector(-1,-1){5}}\put(30,20){\vector(-1,-4){5}}\end{picture}[/tex][/coolcode]
[tex]\setlength{\unitlength}{1mm}\begin{picture}(60,40)\put(30,20){\vector(1,0){30}}\put(30,20){\vector(4,1){20}}\put(30,20){\vector(3,1){25}}\put(30,20){\vector(2,1){30}}\put(30,20){\vector(1,2){10}}\thicklines\put(30,20){\vector(-4,1){30}}\put(30,20){\vector(-1,4){5}}\thinlines\put(30,20){\vector(-1,-1){5}}\put(30,20){\vector(-1