What happened was I got the test all set up, populating the database with a fake album with five images, then calling the function I just fixed to give me five random images from that album.  Before doing this I rigged the next call to rand() to return a Very High Number, such that when the original query is fired, it will definitely not return all of the images, and my new added requery will be required. This was all well and good, but when I ran the test, it kept telling me it was getting back 0 images when it asked for 5. First I thought I needed to force an update of the ImageBlockCache, which is where the random numbers are checked, but it turns out all I needed to do was to generate derivative thumbnails for the test data after I insert it. Whodathunk?

Now that everything is working, though, the unit test is pretty darn cool. Red light before my bugfix, and green light afterwards. Nothing like color-based motivation.

My first Gallery-related task is actually unrelated to my project.  The developers wanted each GSoCer to perform what they called a “familiarization task”, which, as the name implies, is intended to be a way to dive into the Gallery code and way of life.  These were basically small bugs that needed to be fixed (open source projects usually have a long long list of open issues and bugs) that the developers believed someone new to the project could handle.  I believe I have fixed the bug I was assigned, but they also want me to write what’s called a “unit test”–code that proves that my bugfix does indeed work–and I’m having quite a bit more trouble trying to figure that out.  It’s never a good sign when your unit test takes longer to make work correctly than your actual code did, but I doubt this will happen often.  Once I learn the ropes better I hope to be able to crank out tests before I write code that fixes them.  At least, that is the way that unit tests are supposed to happen.

Here’s what I’d like to do: I’d like to merge several PDF files into one, multi-page PDF file. Simple, right? Seems like something I should be able to do in my favorite way to Get Things Done: from the command line, and with Free Software. And indeed I can, with pdftk.

Pdftk is a command-line tool for doing everyday things with PDF documents. Keep one in the top drawer of your desktop and use it to:

• Merge PDF Documents
• Split PDF Pages into a New Document
• Decrypt Input as Necessary (Password Required)
• Encrypt Output as Desired
• Fill PDF Forms with FDF Data and/or Flatten Forms
• Apply a Background Watermark
• Report on PDF Metrics such as Metadata, Bookmarks, and Page Labels
• Update PDF Metadata
• Attach Files to PDF Pages or the PDF Document
• Unpack PDF Attachments
• Burst a PDF Document into Single Pages
• Uncompress and Re-Compress Page Streams
• Repair Corrupted PDF (Where Possible)

Pdftk allows you to manipulate PDF easily and freely. It does not require Acrobat, and it runs on Windows, Linux, Mac OS X, FreeBSD and Solaris.

Wonderful; sounds easy enough. It has a packaged DMG, but the file seems old and contains some odd warnings near it (”this installer does not work on OS X 10.4.0, but it does work on OS X 10.4.1″). Also, I like to build things when I can, so I hop over to the build instructions to find out that OS X users need to build and install gcj in order to build pdftk. Boo. Boo to Apple for not including gcj and boo to pdftk for requiring it.

While I would normally follow this through to the end, it’s getting late and I’d like to get this done and get to bed. The download page mentioned an alternative app for OS X called Combine PDFs, so I will give that a shot.

Some rather amusing German translation on the website, but the program seems to be designed for exactly what I want to do. (Written in Realbasic–intriguing.) Ok, standard .app fair installation (i.e. lack thereof), and straightforward GUI. Click “Add Files…” and … what? I can’t select more than one file in the Open Dialog? Curses! Longing for a wildcard, but also for bed, I click the damn button 39 times and grumble about the scrollbars not remembering their positions. Let’s see whether this app will deliver where it counts…

Beachball… I suppose it is a mac app. I’ll go brush my teeth. After coming back I find the progress bar lost in VirtueDesktops limbo. Understandable; I’m a compulsive desktop flipper–drives anyone who watches me work crazy. Page 14/39…

Well, even if this works, it’s clear that pdftk might still be worthwhile to get working in the future. I probably won’t get around to it until next time I need to do some PDF task. Hopefully then I won’t start so late at night (or by then OS X Developer Tools will include gcj).

Aaaand no text made it through. Wonderful. Well, here goes with pdftk then.

In the interest of sleep I’ll try the dmg first. A nice little Apple Cardboard Box and a readme that lists the files installed. Nice. I think I’ll actually store this readme somewhere in case I ever want to uninstall. Just several dylibs and an executable. Wish I had man pages though. Let’s see how this one does.

Seems the authors forego man pages for a huge (402 lines) output for –help. Time to try pdftk *.pdf cat output howareyou.pdf verbose

Output looks good, but PDF gives same problems with text. Opening just Page 1 with Preview reveals the problem. No text shows up there. Photoshop opens the PDF fine, though. Alright. That’s enough for tonight. Zipping up the individual PDF files and uploading them to Viovio. You win, mysterious PDF format… this time.

This weekend was a trip sponsered by the Marquette en Madrid program to Pais Vasco (”The Basque Country”). On Saturday we went to San Sebastian and I got to wade in the ocean for what I believe is the third time of my life (the previous two times being Cape Cod with Aunt Roe–which was freezing but fun, Boston with Jess–which was windy but wonderful). The weather on this day, however, was beautiful. Katie and I climbed to the top of a huge hill (or a small mountain) and we talked about God and home, and then we walked down the massive beach without giving up and going around when some barefoot rock climbing was involved. I was worried that the trip was going to be awkward and difficult because of my outsider status with regards to the other Marquette students, but each person in the program is individually very nice and I can play the “let’s be social” game without too much trouble and so it all worked out nicely.

Thanks to metafilter and Google Video I just watched a full length documentary called “Scratch” about the history of DJs and “turntablists”. I’m not exactly sure why I ended up dedicating and hour and a half to the thing, but it was an interesting look into the core of hip-hop culture (something which many believe has been lost in the mainstream, a feeling summarized well in this quote: “Guns, bitches, and bling were never part of the four elements, and never will be.”)

Metafilter also just pointed me to an old 1999 Salon article about Donald Knuth, one of the living legends of computer science. I was struck by the closing quote (the title of this article), where Knuth responds to a question about whether his ideas can be applied to disciplines outside of programming. I completely agree with him, and I think it’s a wonderful quote to keep in mind especially for me and my peers as we come to a point in our lives where we must make decisions about our respective future paths.

Traveling in Europe (and a large part of being in Madrid) was and is all about experiencing–observing, examining, paying attention, and sometimes participating.  I think the reason that I can’t seem to write about the experiences I’m having is because they aren’t the kind that have a direct and immediate effect.  When I write here I want something more than just a report of what happened, though sometimes I wonder whether I should be doing more of that.

What good does a report do, though, other than perhaps aid in memory?  I guess maybe that is a worthwhile purpose–something on which to look back later in life–, but I think Future Paul won’t really care much about going back and reading “today we went to get breakfast at this place and I ate X, which was good, and drank Y, which was a little thin for my Taste.” 

So then, what do I write?

The thing is, I am pretty sure I will be without any form of contact with the outside world while we are traveling. I’ve heard rumors that our cell phones don’t work, and I have a feeling that trying to use my already-expensive mobile broadband modem abroad might (a) cause an explosion of some sort, (b) charge me 30€ per minute, or (c) both. This means until April 10th it’s quite possible that I will be out of touch. I’ll look into international calling cards, though… and I’ll probably be making the girls stop at every oasis of Internet I can find in our travels through the European desert. I’m sure they’ll be sympathetic when I begin to show symptoms of withdrawal.

Off to teach the kids and then to study a little more for Syntax.

What have I been up to? Well, life as usual, for the most part. I wake up, I go to school, I go to work, I get home, I eat dinner, I “do homework” (read: zone out on the Internet) and I go to sleep.

Sure, there have been some exceptions to the routine. One weekend, Katie went to the beach with her señora and I managed to end up going out to the biggest club in Madrid until 6am when the Metro opens again, at which point we went out for churros con chocolate. This is apparently a tradition, and I did it as such, and also to make sure that I wasn’t missing out on something amazing by avoiding going to the clubs. Confirmed: yep, definitely not my thing.

Then my parents came for a week, which was a Good Thing. We did a lot of touristy things together, with various guest appearances including Jenny for Toledo and Katie for various things. I decided that my parents are my favorite people to have with me when looking around a museum; they remain interested in the subject matter while also being able to make fun of silly things like St. Bernard and his “special” relationship with Mary. Their visit culminated with a dinner with Gloria where I got to try my hand at translating–it turned out pretty well: no major international incidents, and everyone seemed to like everyone else. It seemed like my parents really enjoyed Madrid and I was glad that they didn’t feel like they had to be in some uncomfortable place just to see me. They managed to get in a decent vacation, too.

The morning after they left, Katie and I hopped in a plane to Barcelona for a weekend of fun, sun, beaches, art, and being sick. Yes, there were two things we didn’t plan for when we bought the tickets and reserved the hostel: (1) that we would both be moderately sick with head colds and various other ailments, and (2) that the Monday that was announced as a no-class day would be retracted, meaning that we would have class. Despite this, thanks to Katie’s flawless planning we were able to have quite a good time in Barcelona and managed to see lots of Gaudi architecture, including Park Güell and La Sagrada Familia. I can honestly say it’s some of the most stunning and enjoyable architecture and design I have ever seen. We also got to see the Picasso museum, which follows the life of the artist, and was an educational experience. The beach and the vegetarian restaurants were fun, too. Being sick, however, was not, nor was running straight from the airport to class on Monday (thanks to the scheduling dosado [which, after several minutes of research, is apparently how that's spelled]).

That brings me to this weekend, which has involved extreme studying vs. extreme procrastination, the writing of this blog post of course being a production of the latter.

So, It’s 1am now and I should get to bed, because I have two tests tomorrow, and I’m not exactly sure if I’m ready for them. Things are moving quickly over here.

One of these days I’m going to find a decent writing style, too… I’m getting a little sick of this clause-y convoluted syntax of mine. I suppose I’ll need to do more writing to stretch that muscle out, though.

First of all, I decided that I wanted to take subjects that I have not already taken in the US, because then I have the possibility of actually learning something, which makes me much more likely to want to understand. For this reason I chose from the classes that are “optativas,” which is to say, optional classes for upper level students to take.

The two that fit into my schedule and looked interesting were Teoría de la Programación and Programmación Concurrente (Programming Theory and Concurrent Programming, respectively). Here was my fatal flaw: on the schedule under “Cuatrimestre” (Quad-tri-mester? Don’t ask me; it works like semester.) both of these classes listed as “1º y 2º”. Silly me took this to mean that the courses were offered both semesters, but I was wrong, oh so wrong.

So yes, I spent yesterday waltzing into year-long classes on topics that are slightly over my head with students who have already been working on it for a full semester. It was awesome.

I struck up a conversation with the girl who sat next to me outside the Aula before class (”Am I in the right place? Oh thank God.” etc.), and she was very nice and helpful. She informed me of the Fatal Flaw and introduced me to the professor so I could ask permission to sit in on class. She also recommended another class she is taking as a better one to sit in on as it is more just talking (less theory and math) and also it is only second semester, so they just started. It’s called Cuestiones Sociales, Legales y éticas a cerca de la informática (Social, Legal, and Ethical Questions in Computer Science) and it sounds like exactly what I want to take.

Note: Here is where Paul works through everything he can remember from these classes to see if he actually understood anything. Apologies in advance for any headaches caused.

So anyways, I was completely lost in Programming Theory as the prof starts by writing this on the top of the board (in terrible handwriting, mind you):

whileor P=skip|x:=<|P1;P2|if b then P1 else P2|while b do P|P1 or P2

When he wrote “else” he turned to me with a half-smirk and said “here we say ‘el-say’, not ‘else’.” I think that this is a semantic (or some term like that) for a language (like all possible statements) and P stands for problem, b probably stands for boolean. They then discussed the difficult last question from their semester exam which was something like:

For while_or does there exist a P,s {s'|(P,s)→s'} that is infinite even though all its calculations are finite? Discuss and give examples.

If you’re at all confused, allow me to share with you that I think s stands for state. Does that help? No? Well, for those of you who aren’t experts in programming theory, the answer is apparently “yes, of course!” The prof explained König’s Lema: All trees with an infinite number of nodes have (at least?) one infinite path (even though the nodes themselves are finite). This applies to calculations and programs as well, and an example of this (I think) is trying to achieve a random number (x := random).

At this point I thought to myself: “Okay, barring lack of knowledge of the syntax and symbols involved, I can mildly understand this!”

Then they moved to while_par (where par is parallel, I learned by asking the girl next to me, so P₁ and P₂ run at the same time). He told the class to develop a semantic for it and the students started writing a bunch of complex looking inference rules in their notebooks, then after 10 minutes the prof asked one student for what he had and they argued about it for a bit and then class was over. Suffice it to say: I was utterly and completely lost. Honestly, after spending 2.5 years in classes which were for the most part way too easy and dull for me, this was kind of a nice sensation.

Next up was Concurrent Programming, where this sensation continued. Now, in Operating Systems I learned the basics of this topic, and this helped me get my bearings a little bit. Also, another important detail. They talked about Semaphores and Conditional Critical Regions and Monitors, and I soaked in and wrote down what I could. This prof spoke even less clearly and had even worse handwriting, but he was very nice to me. When I introduced myself, he asked me if I wanted to come to his office after class to get a syllabus. He then said in heavily accented but very good English: “I would love to teach you Concurrent Programming in English, but unfortunately, because not everybody knows it, I can’t.” I found this very amusing.

After class, he was excited to speak in English with me so that he could practice his. We went up to his office where I learned that the textbook on which the class is based is actually in English. Apparently this is the case with most CS books, as the overlap between those who know Spanish & English enough to translate and those who enjoy CS is small. (So at least I know I have an exciting career option there if I ever need it.) Anyways, in his office the prof started to go over some of what they learned first semester… 15 minutes into this his office-mate (who was sitting on the other side of the room programming in Java on his Linux running laptop and had lived in the U.S. for five years) leaned back and said “Jeez, are you trying to teach a whole semester in one sitting? Give the kid a break!” This is the same guy who snorted when I tried to use the idiom “food for thought” in Spanish, turned around and informed me that it’s a no go in Español. So the prof wrapped up and I talked a little Linux with the other professor (I learned he was running SUSE and had a shelf full of distro-cds from Linux Magazine). They told me I was welcome back to the office any time (the prof said “if you ever are in trouble” and the other laughed again and corrected “if you have any doubts”).

All in all, a major success and a lot of fun.

Speaking of dedication, I find myself with a big tech project looming.  Non-geeks can probably safely skip the next paragraph or so.  It’s going to be interesting, but it’s going to be difficult. I’m working with Pat on a project he’s doing for his Manresa work called “Guiding our children, learning how to pray,” which as you may have guessed is about youth and prayer.  It is a web project focusing on the teen demographic to be used by a local parish’s youth ministry program.  Now I will find out whether or not I can pull off a web design/development job from start to finish.  I’m frantically trying to learn the Django Framework (”the web framework for perfectionists with deadlines” — it’s my latest crush) for the project, which is everything I could ever want in terms of a tool for web development, but I’m just having trouble mastering the dang thing.  The learning curve is steep.

A note about my photos.  I never really liked the way I had them all dumped online as if into a bucket (a photo bucket, perhaps?), so I have decided to take them down while I decide what to do with them.  I’d prefer a little better presentation, swapping quantity for quality.  We’ll see what I think up.

Classes continue.  Nothing new or exciting there.  I am beginning to notice the difference between the group of Marquetters who have classes only Monday-Tuesday (the majority) and people like me who have classes 5 days a week.  For us in the second group, weekends and especially breaks become much more precious, in a way that those in the 5-day-weekend crowd don’t exactly understand.  They can pretty much travel whenever they want, while we’ve had to do things like make lists of all the days we have off and budget which days we are going to have to skip class in order to get in a trip of decent length.  I am pretty sure I’m happy with my decision to have class all five days, but sometimes I am jealous.

When I came out of school today the sun was just setting and it was really beautiful outside.  The temperature was just about perfect, so I decided to take the 10-15 minute walk to the metro stop instead of waiting for the bus to take me there.  It was worth it.

I’m not exactly sure what to think of this pseudo writer’s block or why it is happening. To an extent I bet it has something to do with the way I am experiencing everything here, which is at this point a very let-things-wash-over-me type thing. So when I sit down to actually talk about what has been happening, I blank out, thinking “well, I don’t know… things just go.”

I definitely have a certain desire to organize and present my experience in nice neat little reports with dates and names of places and pictures with captions, but that has been a lot less possible than I originally had dreamt.

The only thing that motivates me to write here now is a paper that I have due tomorrow that is open in the other window. So, I’d better say no more than that I will write here again soon in a more complete way (once I turn this paper in tomorrow I should have more time on my hands). And all you who deserve e-mails: I have been thinking about each of you a lot, even if I haven’t been able to put those thoughts into something tangible.