PCV valve replacement

The back story is like this. I got a 2004 V6 Mazda 6 almost 2 years ago. The engine has been shaking since I got it. Inspected by a dealer and one other mechanic and they think the catalytic converters went bad. The cats for this car are very expensive and probably cost couple thousands…

Install OpenCV inside virtualenv with Ubuntu 16.04

It is a best practice to have a separate sandbox python from the system python. The guide below probably is the simplest way to install opencv inside virtualenv. The drawback though is that it won’t install the latest opencv. But if you just need something quick to get things running, the following probably is sufficient….

Migrating wordpress to different server

I was migrating one of my wordpress site to a new server. I followed this digitalocean post to setup the server initially. It was my first time to try to migrate it to a new server. The following is supposed to work Setup nginx in new server as in the old server Copy /etc/letsencrypt folder…

Git democracy

Came across this inspiring talk by Clay Shirky. He raised the question if we can use Git for open legislation. Just jot down my favorite quotes below The people experimenting with participation don’t have legislative power and the people who have legislative power are not experimenting with participation. They are experimenting with openness. There’s no democracy…

Minimum requirements of a good engineering employee

As title, just some random thought… Able to get things done independently (should be something reasonably complex and takes days or weeks to finish) Care what he is doing and be responsible to his products Good understanding of the current progress of the project and able to communicate this with the team Just to be…

Debugging Torch with Zerobrane

I am kind of new to Zerobrane studio and followed this guide to try to debug Torch code. However, I came across with the error attempt to index a nil value (global ‘utils’) for printf = utils.printf It turns out that the path was not setup correctly. In the config file (Edit | Preferences |…

Problem upgrading Tensorflow under Anaconda

I tried to upgrade tensorflow today. I have a virtualenv for version 2 installed under anaconda 3. If I simply run pip install -U tensorflow I got error like Cannot remove entries from nonexistent file /home/user/dummy/anaconda32/envs/tst/lib/site-pack ages/easy-install.pth It turns out that this appears to be a bug from Ananconda, adding “–ignore-installed” seems to be able…

Virtualbox usb not detected

It is quite annoying that usb does no longer work out of the box for Virtualbox with ubuntu host. The issue seems to affect multiple Linux distros. As of version 5.1.18, it seems that the bug is still not fixed. The workaround is not very complicated. But it is a nuisance nonetheless.   Update: If…

Xournal for presentation

I am using more and more beamer this year. Since I used linux, I used to use evince to display my slides. But in my last class, I would like to write something on the slides and I was not prepared for that. My laptop is a nice good old X230t with a stylus on it….

A simple voting example with node.js

Backstory It started that I would like to have my students to vote for their peers’ presentations. And I don’t like to do it the old fashion paper way. I thought of using some commercial products. But since I was reading a little bit JavaScript couple weeks ago, I guess it probably would be a…