経験分布函数 ref: http://qiita.com/kyoro1/items/cf2396acfb212d2ea852

file0.txt

I(x;a):= \left\{
\begin{array}{l}
    1, x\ge a\\
    0, x< a
\end{array}\right.

file1.txt

G(x):=\frac{1}{n}\sum_{\alpha=1}^{\infty}I(x;x_{\alpha})

file2.txt

\frac{I(x;a)}{dx}=\delta(x-a)

file3.txt

\begin{eqnarray}
I(x;a)
&=& \int_{-\infty}^{\infty}\frac{dI(x;a)}{dx}dx \\
&=& \int_{-\infty}^{\infty}\delta(x-a)dx \\
&=& \left\{
\begin{array}{l}
    1, x\ge a\\
    0, x< a
\end{array}\right.
\end{eqnarray}