tutorial

Simple exercises with grep, sed and awk in org-mode

For text processing, I had never bothered to learn classic Unix tools such as sed and awk, because I can always use Python's regular expression library. The syntax of sed and awk just appeared to be too arcane to me. However, recently I realize that for many simple ad-hoc tasks, even writing a Python script is too much overhead. This motivated me to learn to use regular expressions directly in the command line.
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Writing the Emacs configuration script in org-mode: a simple example of literate programming

Program like writers do Programming is traditionally seen as an exercise that translates human thoughts into a format that computers can understand. As a result, the ideas behind the program can become obscured and fragmented in the source code. This is why reading code requires so much mental effort. For me, reading code often feels like solving a puzzle, or reading modernist/postmodernist novels where events are narrated out of sequence. The concept of literate programming was introduced by Donald Knuth in the 80’s to address this issue.
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How this website was built - a tutorial

I started this website in 2018, because I wanted to collect all my content in one single place. I decided to built it with simple tools, so I could understand how everything works, and fix problems if needed. It’s a hobby like how some people like to build their own kitchens. Lots of tutorials are available on building personal websites, but I still want to write my own, because when I got started, I could never find one that explained every step needed to build a complete website.
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How many photons get into your eyes?

A recent paper shows that our vision is so sensitive to light that human subjects can detect the presence of one single photon shot into their retinas. While scientists have been trying to establish the lower limit of visual sensitivity for a very long time, and it is generally accepted that a small number of photons are sufficient for detection since the 40’s, new advances in quantum optics finally allow us to manipulate light at single photon precision, and it is the first time that direct evidence for single photon sensitivity is demonstrated in a psychological experiment.
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