Change resolution with terminal (Ubuntu 16.04 and Thinkpad x230)

Getting nostalgia and suddenly would like to play a round of old StarCraft. I have upgraded to 16.04 since last year and couldn’t set resolution to 640×480 from Displays setting. But simply using xrandr -s actually works: xrandr -s 640×480 I can then recalibrate the stylus with the usual Wacom Tablet setting.  🙂

SageMath

Trained as an electrical engineer, I am most comfortable with Matlab in terms of serving my math need. However, for symbolic math problems, Matlab is not as intuitive as Mathematica (of course, we can still do it though. Check out “syms”). But I never get used to the syntax of Mathematica. And I found the…

Install Ubuntu to Nvidia laptop

I tried to install Ubuntu 18.04 to MSI  GS43VR 7RE laptop. It is a laptop with GTX 1060 gpu. I kind of expected hiccups with installation. Actually, I couldn’t even get Ubuntu to start with plain installation. The culprit is NVidia driver as expected. Adding “nomodeset” to boot option fixed the problem.  One may also…

Install Gogs on 16.04

My goal is trying to setup a git server along side with one of my existing sites. Say my site has a domain name example.com. I want to setup a git server at https://git.example.com.  I chose Gogs as it is quite light-weight and it appears to be sufficient for me. For security purpose, I tried…

Reinstalling ubuntu packages

I lost my mariadb root password and the recovery process does not work after many tries. Since I was not actually using any databases on that machine. I decided to simply reinstall MySQL server. But just running sudo apt purge mysql* didn’t clean up everything. I still got configuration errors when I try to reinstall…

apt update fail after installing Jetson library on host computer

As title, the issue is “fixed” by adding  [arch=amd64,i386] just after deb on every deb line in /etc/apt/source.list as suggested here. However, note that some deb lines may be included under the folder /etc/apt/source.list.d. So don’t forget adding [arch=amd64,i386] to them also. Another fix mentioned here is to remove the arm64 architecture completely. sudo dpkg –force-architecture –remove-architecture arm64 It did…

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…