Understanding even the most complex shell commands


The website explainshell.com has a very simple goal: enter any shell command and it will explain the string bit by bit. It is extremely useful if you are starting out with Linux and still don't know your way around the terminal, but it is still quite handy for more advance users.

Take the following shell command: echo "YALNEB.BLOGSPOT.COM" | sed 's/LO.*T/y/g;s/COM/Andres/g' | tr '.' ' '. It is quite ugly to look at, but all it does is print: YALNEB By Andres. How? Well, it's really simple! Take a look at the explanation and you will see how ingenuous this script actually is ;)

Audiophiles on Linux, rejoice

PulseEffects screenshot taken from their official git repo

Suppose your an audiophile (at least level 2) and want to fine-tune your equalizer to improve your headphones play back on Linux. You are after that super clean and real-life-like flat response where the bass sounds realistic and the mids are super crisp. How to you go about it?

Well, there are many ways. But if you combine PulseEffects, a system wide parametric equalizer with GUI for Linux, and AutoEQ/Results, a huge database of precalibrated headphones, you will be set in less than 5 minutes.

Bash terminal greeter


Wouldn't it be nice that every time you open up a terminal (or log in remotely), you would be greeted by a general overview of your system's health? Well, with this tool you can address this very problem.

This is a simple bash script that displays on top of new terminals a simple summary of your system's specs (useful if its a remote machine you just logged in) and a summary of your systems current load. Moreover, if the load is high, the color will change to draw your attention quickly, and when possible, will display what is causing the problem. Such as a report of CPU hungry processor an error report if a systemctl service has failed to load.

Xiph.org - Excellent videos on digital multimedia

Sometimes you find absolutely outstanding videos on the internet. Such is the case of a brief video series by xiph.org on digital media. The host explains with very visual examples some concepts that are always misunderstood when comparing analog audio to digital, like that there is audible signal quality loss because of the conversion (not true). My favorite take-aways have been:
  • Why 22 bit audio has no real advantages over 16 bit (for playback).
  • A better understanding on the noise-level of digital audio and the effects of dither.

Really, if you consider yourself an audiophile of level 3 or beyond, you really should watch his videos to deepen your knowledge about the joys of high quality media playback.

A comprehensive introduciton to hypothesis testing


If you are working on a Ph.D, no matter what knowledge area, you will sooner or later encounter hypothesis testing to prove (or disprove) whether your suspicions hold true (is a system more stable, does a medicine work better, are there diferences in the carbon-dating results, etc.). A such, you will find this introduction to p-values using catan and dices extremely insightful. Its extraordinarily well (and fun) written, contains many hints, and warns you about common mistake you might be committing in your own research. I hope you enjoy it.

[DISPROVED] My thougts on gavitational waves and ETI


One of the greatest breakthrough of applied science in my lifetime happened relatively recently: we detected gravitational waves. In essence, we have detected a grativational "ripple" of gravity; much like you would feel your boat rock in a still pond if someone were to throw a heavy rock into it. But regardless of how amazing this is, it is also extremely sad.

Tiddlywiki - A starting point with all extras

My intention for this post is to be a single entry point to access an empty TiddlyWiki (in terms of contents) but preconfigured with all extras, plugins, and tweaks I may come up with. So that you might always find my latest version here, including my own tweaks as well as those by third parties I'm planning to talk in the future about.