piatok, 9. septembra 2016

Opening, Advice & Congratulations

It's remarkable how people shape the form of ceremonies. When Sapo spoke at the opening Academy Assembly, he was in his measured and insightful mode. His main point about the need to make our own decisions based on the self-knowledge, and not just take advice that might be offered liberally, was a profound one. Philosoraptor notwithstanding. (A cynic might say he closed the last niche for educators – since we are neither providers, nor custodians of knowledge, and decisions need to be taken independently, what should we do? Let's leave this challenge unanswered for now.)
And what about art? Francis recited a poem (and thus ensured the existence of the Spoken Word club), and David Králik came up with another of his musical masterpieces. Sing along to a well-known tune:

Happy birthday to us,
Happy birthday to us,
Happy birthday LEAF Academy,
Happy birthday to us.

If you think this is not grand enough, you might disregard the fact we are not so fond of glitter and spotlights. And do not be surprised to read the Academy absolutely loved it.

štvrtok, 11. augusta 2016


A shoggothing pretender.

How would one name an object of a post-apocalyptic appearance with a niche use, and utterly unfashionable in the traditional sense? A shoggothing.
There is no doubt shoggothings have their use. Take a gas mask. Great for a field training, military, anti-globalist demonstrations, but in the main it is an awful, space-occupying oddity with of a China Miéville nightmare. In short, a true shoggothing.
If you require a Slovak rendering it’s straightforward: šogotina.

piatok, 22. apríla 2016

Running – Biology in practice

Even a runner's body produces energy in this way.
Since my High School I have been a fan of ceteris paribus – "given all other factors unchanged". Today I came to feel again that sometimes it does not hold, and the results do not approximate the expectation.
I went for a good run on Tuesday night. I did not expect the weather to be so windy and cold, so I had to put on a hoodie (I never do). It was in the evening; I was a bit tired: hardly ideal conditions. After a few kilometres on the city pavements, I hit the runners'/cyclists' lane and could accelerate. The whole run felt very good, I covered 13 km at 4:41 min/km. The last 10 km were at 4:41. Here are the data:

km avg. pace
1 05:11
2 05:08
3 05:00
4 04:49
5 04:37
6 04:44
7 04:40
8 04:29
9 04:29
10 04:31
11 04:30
12 04:30
13 04:23

avg. 04:41

I knew it was a useful workout. So over the week I thought about replicating the intensity. This morning I got a chance to run, so I put on my running shoes and set off. I intended to hold back for the first two kilometres, then accelerate to 4:30/km, and fade out to 5:00/km at the end, all in 11 km. The conditions seemed perfect: I was fresh (morning), had better shoes on (I did run in fivefingers the other day), and did not need a hoodie! Yet it did not work out as planned:

km n. avg. pace
1 04:46
2 04:47
3 04:30
4 04:36
5 04:39
6 04:54
7 05:32
8 05:07
9 05:32
10 05:27
11 05:09

avg. 04:59

What happened? Based on my feeling during the run I suspect the two important factors (the ceteris paribus not met) working against me were energy and tiredness. I avoided running hungry on Tuesday by eating two snacks (horalky) about half an hour before the run. This morning I had a banana (and not much last night). Perhaps unsurprisingly, I felt like unable to keep with 4:30 at kilometre 4, and 5, and all but abandoned the ambition of 6 or 7-km span at 4:30. It felt a bit like in some marathons: you will to go on or accelerate, but the return is modest. Cardio feels ok, but the legs do not respond well. Empirically, this would suggest that two (early) horalky are better fare than a banana. More importantly, a half-empty stomach is not good enough. 
The other factor is tiredness. Had I felt soreness in my muscles, I would not have been so adventurous. Still, I must have forgotten Pfitzinger's rule of thumb for tempo runs or long runs: keep 4 days between them (P. Pfitzinger: Advanced Marathoning). I did not. I'll learn.

Perhaps I will be able to get close to 7-10k at 4:30 soon. Obviously, I need some time off first.

utorok, 5. apríla 2016

Programming is thinking!

"In search of a new car, the player picks a door, say 1. The game host then opens one of the other doors, say 3, to reveal a goat and offers to let the player pick door 2 instead of door 1." Taken from wikipedia
A colleague of mine, Lisa DiIorio like saying that writing is thinking. A part of me tends to disagree fiercely, but I still have to find solid evidence that it is not. If I really wanted to argue, I might start proposing writing Vogon poetry or something woefully associative and irrational. On the other hand, I have seen how right she might be. Today Lisa's mantra showed her truth when I tried to solve an old puzzle by ogre-like piece of programming.

I distaste the Monty Hall problem profoundly. My main reason is that it does not figure intuitively. In order to get a reward (a car), you are to guess the correct one of the three doors. As soon as you make your choice (say 1 or 2 here), you are shown that one of the options you have not chosen (3 here) does not get you the reward (a goat is not considered a reward). Should you switch?

I have remembered that I should switch since a student presentation in 2013, though I did not find the argument (proof) easy to reproduce. And it sounded arcane. Similar to the statement that DNA-helicase splits the double stranded DNA – it's name is -ase (analysis), DNA is double-stranded helix ... guess it figures.. I had less enthusiasm for the Monty Hall switching strategy because it lacked even nominal sense. (I did not forget about the proof.)

Thinking about an introduction into probability, Monty Hall came up today. I dared to ask myself – can I look into it properly? I told myself it would be best to write a simulation testing the two alternative strategies: switching vs. not-switching.

The basic architecture of the program is simple: generate N (~1000) random integers between 1 and 3. Do it twice: the first set (array) corresponds to secret locations of the car (Reward), and the other corresponds to the Guesses. Call the strategy function with the two pieces of information and your choice of strategy (not switch or switch) to get your success rate. What does the evaluation (strategy) part function do?

For case of non-switching, it compares corresponding elements of Reward and Guesses and calculates the frequency of such occurrence. By virtue of Law of large numbers this should be close to 1/3.
Let's look at the switching. There are two cases. In the obvious one (A), my original guess was correct, but I dutifully switch to a non-reward option. Bad. In the other case (B), I was wrong, and as I am shown the other incorrect option, I choose the right one.

As I was about to start coding the switching part, the proverbial light-bulb seemed to light up. The probability of the first scenario (A) is 1/3, and it gives me goats. Zero. On the other hand, the second scenario (B) occurs with probability of 2/3, and I always win there. Eureka!

Even though I have a proof, I still run the the program. Winning in 66.75% for a switching 33.19%  for non-switching for runs of 100,000 tries. Job's well done. I suppose I understand the MH puzzle/paradox a bit better.

I guess programming is thinking as well:)

sobota, 19. marca 2016

Respect at Nueva School

Paul Klee: Two Men Meet, Each Believing the Other to be of Higher Rank, 1903

In class
Student: It is easy to find the expression for an ellipse which is symmetric around origin. Consider you have to keep the distance from the two fokai...

Teacher (unrecognised): Fosee. 
Student: It's awful to correct others, you know?
Student (recognising what has happened): Sorry...

After the class (all have left)
Student: Anna, I apologise. I do did not mean to...
Anna (teacher): It's forgiven. Just be careful talking angrily at people in future.
Student: Thanks, bye.

Matus: Aron, what is the school policy for students using phones?
Aron: Strange that you are asking, you are not the only one. There is none.
Matus: You know during the talk, I saw no one at my table using it! And it was not a short talk...
Aron: They would not be on their phones, as it would be disrespectful to the speaker. The same applies for in class: using a phone there would not be respectful to their teachers.

Simple, isn't it? I am delighted I could see a school where the idea of respect is so manifest.