About me

  • I was born on 1974, in Spain, and have lived there most of my life, except for five wonderful years in Germany and several stays abroad.
  • I have studied Physics, did the Ph.D on that and have since worked as researcher in several institutions.
  • I now live in Madrid and work at the Spanish Research Council.
  • Programming has alwas been a passion. I have worked on multiple projects, all of them related to free software.
  • Hobbies: playing the guitar, sports, reading, languages and travelling.


  • Do no take this seriously. It is just a space to collect information, texts, photos and other stuff that me or somebody else might find useful.
  • Everything that I write here reflects my own personal opinion or experiences and is in no way endorsed by my employer or colleagues that might be mentioned in this blog.
  • All the information provided here comes without any kind of warranty. Use it judiciously and critically.

Recent programming items

  • Solving fermionic Hamiltonians In our daily live as a quantum physicist, a very routine task is to solve fermionic problems: from computing ground states to time evolution. It happens to me often enough ...
    Posted Apr 29, 2015, 12:19 AM by Juan Jose Garcia-Ripoll
  • Profiling code with 'perf' This is an incomplete summary of the steps needed to profile C++ programs using Linux's perf tool, a fantastic profiler that samples your program and sees how much time ...
    Posted Apr 6, 2015, 5:06 AM by Juan Jose Garcia-Ripoll
  • LaTeX equations in LibreOffice (Windows) Unfortunately, recent editions of LibreOffice have problems with rendering equations that contain complex symbols, such as sums, products, arrows, superindices, overbraces, etc. There are workarounds to this, which involve mainly ...
    Posted Feb 1, 2015, 10:18 AM by Juan Jose Garcia-Ripoll
Showing posts 1 - 3 of 5. View more »

Recent musings

  • Staedler Mars Matic 700 (Refillable technical pen) One of the things I always wanted to try is combining watercolor and ink. This has many applications, from beautiful sketches (See Russell Stutler's page for paradigmatic examples), to ...
    Posted May 3, 2015, 3:15 PM by Juan Jose Garcia-Ripoll
  • Rotring Art Pen EF Review I have an objective of doing at least one sketch a day, let it be an exercise from Pen & Ink Techniques, a copy of one of Alphonso Dunn's examples ...
    Posted May 1, 2015, 12:47 AM by Juan Jose Garcia-Ripoll
  • More Tachikawa School-G sketches Following up on my earlier review of the Tachikawa fountain pen for fine Manga drawing, I have continued using it on my daily drawing exercises. The sample below, about half ...
    Posted Apr 26, 2015, 11:35 AM by Juan Jose Garcia-Ripoll
  • Art fountain pen: Tachikawa School-G (review & fix) In the last months I have rediscovered the pleasure of drawing and sketching, assisted by tools that I normally had disregarded by those tasks, such as my conference notebooks, rollerbals ...
    Posted Apr 26, 2015, 12:23 AM by Juan Jose Garcia-Ripoll
Showing posts 1 - 4 of 4. View more »