## 问题¶

\begin{align} f(n, 0)&=n\\ f(n, 1)&=n(n+1)/2 …

## Normalize color by center

In [3]:
from matplotlib.colors import Normalize

class CenterNorm(Normalize):
def __init__(self, vc=0, cc=0.5, vmin=None, vmax=None …

## GNONE插件¶

https://extensions.gnome.org/

### 次要¶

• Bumblebee Status by dsboger
• gTile by scherepanov
• Media …

## Windows设置

• 压缩7-zip
• pdf阅读器
• WPS
• 图像处理
• 代码开发
• 浏览器
• 编辑器
• 网盘dropbox, megasync
• 词典 …

## 描点画图

### 等距描点画图¶

\begin{align} \Delta l&=\sqrt{\Delta x^2+\Delta y^2}=C\\ \Rightarrow \Delta x&=\frac{\Delta l}{\sqrt{1+y'^2}} \end{align}

### 等角描点画图¶

\begin{align} \theta&=\arctan …

## Network Programming

• Generally, it is stored(Big endian) in a struct in_addr rather than a scalar value.

struct in_addr {
unsigned int s_addr; /* Network byte order (big-endian) */
};

• To convert …

## Frames Export¶

Get frame rate information

videoname=T-L\ _\ 1-50\ tip-tip.avi
ffmpeg -i $videoname 2>&1 |grep -o '[0-9]\+ fps'  The output is 30 fps ffmpeg -i$videoname …

## Aim¶

Minimize $$\sum_i \mathrm{distance}^2(\vec r_i, \mathrm{line})=\sum_i (\vec r_i\cdot \hat n-\rho)^2$$ for line $\vec r\cdot \hat n-\rho=0$. It is equivalent …

## ipynb2pelican Plugin released!

Yet another Pelican Plugin for blogging with Jupyter Notebooks using MetaCell to store metadata.

Thanks to super cow power of python, we can finally publish ipynb easily! Below is the …