This tip is about camera related coordinate system in android. When i develop camera related apps, inside onPreviewFrame() i need to do image processing on byte[] data and show results on top of the canvas and i use OpenCV for the image processing in jni. So the whole workflows is ...

Vim

cheatsheet, right move, My Vim and NeoVim dotfiles

This tip is about how to make pyqt4 rectangle selectable by its edge (or you call it stroke), by default it's selectable by inner area. To achieve this, basically you need to subclass QGraphicsRectItem and overwrite its shape() function so that its shape is not an area but a ...

This tip is about how to update matplotlib plot, it is based on this great tutorial: Speeding up Matplotlib

I learned two ways of updating matplotlib plot, both require first manually change the content of objects that to be updated. For example, lineObj.set_ydata() for line object, vlinesObj.set_paths() for ...

This tip is about using wingide 's debugger to debug your python code. Sometimes the python code can run from terminal but not from wingide ui, it mostly is because the python related environmental variable settings are different when python kernel is start from terminal and from wingide. In this ...

OS: OSX 10.10 Yosemite

enable screen sharing

• Remote Management vs. Screen Sharing?

connection from client

• if client is Apple, simple: open vnc://ipaddr

• if client is Linux or Win, sounds simple: vncviewer vnc://ipaddr, possible issues:

  • no matching security types mac, solution: make sure a vnc password is given ...

[Hardware] Beginner's Configurations

• EVGA Nvidia Graphics Card variation explaination

  • ACX 2.0+: advanced air cooling system
  • SC: slightly super clocked
  • Classified/FTW: highest super clocked
  • Hybrid: water loop cooling system
  • BP: pure esthetic considerations, black plate
  • K|NGP|N: pre-binned gpu
  • ideal options: GTX980Ti ACX 2.0+; GTX980Ti SC ...

install tigervnc

yum groupinstall Desktop
yum install tigervnc-server

modify /etc/sysconfig/vncservers file

VNCSERVERS="1:user1 2:user2"
VNCSERVERARGS[1]="-geometry 1024x768 -localhost"
VNCSERVERARGS[2]="-geometry 1920x1080 -localhost"

-localhost option is to make vnc encrypted through an ssh tunnel

modify /etc/sysconfig/iptables file

add one line:

-A INPUT -m ...

This will be the logs of my struggling in fixing all kinds of messy bugs

01/03/2015: converting ipython notebook into html, style is ugly, math symbols and tabels in markdown cell are not rendered, no title of the html page

Reason:

• I was using ipython 1.2.1 ...

Machine Learning

• EBooks
  • My Colletion
  • bookfi for free ebooks
• Tutorials && Courses
  • General Machine Learning
    • Machine Learning
    • Coursera by Andrew Ng, by Hsuan-Tian Lin fundation and techniques
    • Machine Learning @ CMU by Alex Smola 2013 2015
    • Elements of Statistical Learning @ KTH
    • Advanced Topics in ML 2004, Kernel and Embedding Methods in ML ...