The new 4.19 kernel is causing trouble

A "kworker" process is hogging my CPU. I have to go back to 4.18 kernel to resolve this issue.

UPDATE (01/24/2019)

The solution is amazingly simple. Follow this post:

1. Install perf;
2. sudo perf record -g -a sleep 10
3. sudo perf report

Scrolling down the records, it looks like the problem is related to my USB hub. Unplug the hub and the problem goes away. 

Good tmap examples

I learned a lot from this.

How to increase graph resolution in Rmarkdown and more

Very useful information here.

Animate a line plot

This is very helpful.

Visualization and animation

Fascinating resources here.

Installing VMware workstation 15 on Manjaro

A few things to notice:

1. Need to install Linux header files;
2. Consult the pinned comments here.

A few useful commands:

• sudo modprobe -a vmw_vmci vmmon
• sudo vmware-modconfig --console --install-all
• sudo systemctl enable vmware-networks
• sudo systemctl start vmware-networks
  

Zapcc with Rstan

I use the brms package, which uses the standard R formula syntax to generate Stan code, which gets translated into C++ code by rstan, get compiled and executed. In this process, a optimized C++ compiler can make a big difference.

Here I ran the brms sample code for the spatial simultaneous autoregressive (SAR) sample code using clang++ and zapcc and benchmared the performance (three times):

clang++: 66.89 (lagsar), 49.02 (errorsar)
zapcc: 56.80 (lagsar), 18.43 (errorsar)

Such a performance boost can be achieved by simply switching a compiler!

Statistical Rethinking with brms, ggplot2, and the tidyverse

Amazing resource here. Great book, very exciting!

Arch-Data-Science

Data science toolkit for Arch and Arch-based system here.