TeXtalk: an interview with Gonzalo Medina

Hola amigos, welcome to the TeXtalk! We have a very special guest for today: our friend Gonzalo Medina, one of the most active members of TeX.sx, trusted user (44k+ rep), with 849+ answers so far and 208+ badges. Get ready for this great interview!

Paulo Cereda: Could you tell us a bit about yourself?

Gonzalo Medina: I am a 42 year old Colombian mathematician and father of two (a 16 year boy, Olmo and an eight year girl, Sara) and I am currently a professor at Universidad Nacional de Colombia, where I teach  math courses to undergraduate and graduate students; I also teach a LaTeX course every year since 2009.

I belong to the Scientific Computing and Mathematical Modelling research group of my Department. My main interest is in algebra, but recently I am beginning to develop an interest in the history of mathematics.

Paulo: How nice! Do you have any hobbies?

Gonzalo: LaTeX is my main hobby. I love reading; I also play classical guitar and used to play basketball. Unfortunately, due to that combination, ten years ago I injured my left hand pinkie and now I can only play simple scores on the guitar.

Paulo: Sports-related injuries can be very annoying.


Gonzalo: Indeed.

Paulo: What was your first contact to TeX, LaTeX and friends?

Gonzalo: I joined the party a little late. Back in 2000 I started using LaTeX for writing exams and lecture notes; in 2003 I started my first “big project” writing an introductory text about the theory of representation of ordinary posets; I finished the text and used it in one of my courses, but unfortunately, I lost the files in 2007.

Until 2007 I was only an “end user”, but then I needed to do something I didn’t know how to achieve, so I found a forum on the internet and asked the question there; the question remained unsolved, so I started searching for myself until I found the answer, and that’s where it all began!
I started reading package documentations, and answering questions on that forum (where I met Stefan Kottwitz) and then I found latex-community.org, so I became a member also and participated actively.

Paulo: What a great start!

Gonzalo: In 2008 I bought The LaTeX Companion and started reading it and learned a lot from it. Last year I finally bought The TeXbook and I am starting to study it.

Of course, during that time I also read and studied some code (the standard classes, some packages).

Paulo: How did you become aware of the TeX.sx community?


Gonzalo: Two years ago or so I, for an unknown reason, stopped visiting latex-community.org and the forum where I took my first steps disappeared. One day I googled something I needed and found a reference to TeX.sx so I took a look, and I liked it. My first post here was a question. Then I started answering questions… and here I am.

Paulo: I am always impressed with the vast knowledge you have about packages and their use. Out of curiosity, how many packages do you know by heart?

Gonzalo: I don’t think I have such a vast knowledge; I simply know some of the packages that are around and read the documentation and code of some of them. To be honest, I only know just two packages by heart and they are precisely my own packages.

And even with my own packages I keep forgetting things and have to reread the code.


Paulo: speaking of your own packages, could you tell us a bit about them?


Gonzalo: The


package was born out of personal needs. One day I needed a background image for some pages of a document, so I took a look at the available packages; for some reason or other, none of them were fit for my problem and I noticed that none of them used the power of TikZ, so I decided to write a package and


was born.



package was born out of a challenge. Someone asked a problem in a forum about automatically getting a zebra-like pattern for text paragraphs, so I started reading and trying to find a solution to the problem. At some point I got stuck, so I asked a question in


and Philipp Stephani pointed me in the right direction: a method described in TeX by Topic to dissect paragraphs. A few days later,


was born.

Paulo: Cool! Any new package in the oven?


Gonzalo: I have some ideas, but not enough time. We’ll see.

Paulo: You submitted a fantastic entry to the birthday contest. Very beautiful typography! Do you use this template in your lecture notes?


Gonzalo: Thanks. That was actually an idea that Yiannis Lazarides gave me to participate in the contest.

I eventually use it, with less color, for some documents for my students.

Paulo: Trusted user (44k+ rep), 849+ answers, 208 badges. What’s your secret?


Gonzalo: I don’t really know, myself.


Whenever I can, I try to provide complete answers (although sometimes I wish I had more time to improve them), and I guess the community notices it.

Paulo: What’s your favorite workflow when TeXing (editor, tools, engine)?


Gonzalo: I currently use TeX Live and TeXworks.

Paulo: Do you have a favorite answer of yours?

Gonzalo: The first one that comes to my head is the answer to Pretty Table of Contents. I liked its simplicity. There are some other answers that I like, but I cannot remember right now which ones exactly.

Paulo: Can you name something you really like in LaTeX? And is there something you dislike?


Gonzalo: I like a lot of things. Perhaps I can summarize all the things that I like in a (very well known, even “cliché”) affirmation: LaTeX gives complete control over the attributes of the documents.

And perhaps one thing I don’t like is the coexistence of fragile and robust commands.

I should mention that I don’t fully agree with the use of “complete” in the affirmation I mentioned above.


Paulo: Oops.


Ready for LaTeX3?


Gonzalo: No, not really. A couple of times I’ve used the features provided by


and I really like the increased functionality and ease of use. However, I still haven’t ventured to use the new syntax; I once took a quick look at the code of egreg’s


and found myself lost, although the general idea was understandable. I have to start reading new documentation! Anyway, I am really happy to see that LaTeX3 has made some big progress and hope to see it “presented to society” pretty soon.

Paulo: How about LuaTeX?


Gonzalo: I only know that it exists and that it seems to be powerful.

Paulo: We’ve seen great keynotes about TeX and friends presented by TeXnicians all around the world. Do you think Latin America could host a TeX User Conference?


Gonzalo: Yes, I positively think so and I think it would be really important to hold a TUG conference in Latin America. I had some ideas about proposing Colombia for the 2013 meeting, but due to some issues beyond my control, this idea will have to wait a little bit more before becoming a reality.

Paulo: It would be great!

Gonzalo: Sure it will be.

Paulo: What do you recommend for a newbie eager to learn TeX, LaTeX and friends?


Gonzalo: (1) To take their time; if they want to learn LaTeX for a project due in two days, it’s gonna be a nightmare. (2) If taking a course is not an option, then they should get a good manual (there are some really good ones around). (3) Not to use “templates” from other people; this will prevent them from really learning or, even worse, will show them bad practices. (4) Experimenting. This is how you really learn everything. (5) When problems appear, they should try to solve them by themselves and if they can’t, then seek advise somewhere with quality answers (in this community, for example).

Joseph Wright: Any particular favourites for (2)? Books, websites…

Gonzalo: For an intermediate-advanced level in LaTeX, I would suggest The LaTeX Companion.

Paulo: Speaking of manuals, how was the experience of translating


to Spanish?


Gonzalo: It was a nice experience (I learnt one or two things about LaTeX when I did it) and I did it hoping to make this document more accessible to Spanish speakers who can’t read in English, German, French or Italian. The translation now is obsolete (it doesn’t correspond to the new version of


) and I will have to update it.

Paulo: Thanks a million for this great interview! Muchas gracias!

Gonzalo: Thanks to you, Paulo! It’s been a pleasure and an honor. ¡Gracias a ti, Paulo! Ha sido un placer y un honor.

Paulo: The pleasure and honor are mine.


Stay tuned for the next episode of TeXtalk!

4 thoughts

  1. Dear Sir Gonzalo Medina, please accept my sincerest appreciation for the wonderful work you are doing in helping the TeX lovers all over the world. I always prepared my documents in LaTeX, but did not really explore Beamer for presentation, as I always found myself somewhat confined in the themes. But with the help of your insightful posts, now I know how to manipulate the designs. Thanks a lot. We pray for your good health.

  2. I have little time to work with Latex. Much of my progress must be debited the kindness of Gonzalo in help.

  3. Hey
    I face a problem with beamer, the items for TOC for the first frame is adherent with the footer and the next frame with TOC looks good, How can I solve this cosmetic problem for TOC’s items at the first frame.

    \begin{frame} [allowframebreaks]

    \frametitle{Outline for section \thesection}


    Marwa El Diwiny

  4. Dear Sir,
    I am facing a problem while adding more than 9 child in the following code (posted by you)

    When I added 10th child, it is showing following error-
    Package pgf Error: No shape named c210 is known.

    See the pgf package documentation for explanation.
    Type H for immediate help.

    l.103 \draw[->] (c2.195) |- (c2\value.west);

    Please help.
    Thank you in advance.

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