a thought abroad

Fixing my Logitech MX Vertical mouse

Sun, 13 Sep 2026 11:21:04 +0000

Left click. Nothing happens. Left click. Nothing. Time for a new mouse? No. Instead, I repaired my Logitech MX Vertical mouse after many hours spent on troubleshooting, desoldering, soldering, and tinkering. But it was as educational as successful. Left click. Bliss! The mouse works again.

Autoland

Thu, 09 Apr 2026 13:29:34 +0000

How to build a controller that automatically lands an airplane after approaching a runway via the Instrument Landing System (ILS) in GeoFS, the flight simulator?

ILS, Follow the Glide Slope

Thu, 12 Mar 2026 13:10:15 +0000

How to build a controller that automatically puts an airplane on the glide slope from the beam of the Instrument Landing System (ILS) in GeoFS, the flight simulator?

ILS, Follow the Localizer

Mon, 09 Mar 2026 07:26:03 +0000

How to construct a controller that automatically aligns an airplane with the runway using the deviation from the localizer beam of the Instrument Landing System (ILS) in GeoFS, the browser-based flight simulator?

Where is the Runway?

Mon, 23 Feb 2026 03:44:01 +0000

Can’t spot the runway in GeoFS, the browser-based flight simulator? I fixed it by extending GeoFS with Google Maps, showing thousands of airports, as well as the extended centerline of the runway at the destination on the map.

Virtualizing the Controllers

Mon, 09 Feb 2026 11:39:52 +0000

A little quest to get every single button on my throttle quadrant to work with GeoFS, the browser-based flight simulator. A quest that not only taught me a little bit about evdev in Linux, but also led to many more quests later on.

Controls, Yours Or Mine?

Sun, 08 Feb 2026 06:26:15 +0000

Discovering all kind of difficulties of controlling the aircraft in the GeoFS flight simulator. As well as some remedies, whether in adjustments to software, hardware, or simply through deliberate practice.

Foraying into Flight Simulation and Control

Sun, 08 Feb 2026 00:29:31 +0000

A session with the flight simulator turned into a both entertaining and educational quest into control theory. Topics that I haven’t dabbled with for one, two, or even more decades. From a self-imposed lockdown to my first attempts to use PID controllers and fuzzy logic for steering the aircraft in GeoFS.

Swiss Peaks 170, En Route

Mon, 15 Sep 2025 13:15:51 +0000

Rain arrived, plenty of it. Then some thunder. The inflatable portal set up outside of the life base in Lourtier is rocking back and forth in the wind. Clouds appeared. Mountains disappeared.

Swiss Peaks 170, Gear Check 123

Sun, 31 Aug 2025 06:57:19 +0000

Long races in the mountains require gear. Such is the case with Swiss Peaks 170 as well. Worth thinking about how to arrange things so I can stay focused before and during the race, and take care of myself after the race.

Swiss Peaks 170, The Days Before

Sun, 24 Aug 2025 06:27:33 +0000

Less than two weeks to go to Swiss Peaks 170. Time to reinforce the idea that the training is done except for the taper. Time to reinforce the idea that I am prepared, no more, but also importantly, no less.

Swiss Peaks 170, Upcoming

Tue, 24 Jun 2025 13:37:37 +0000

One year break from racing Swiss Peaks taught me nothing except that I need to do it again. This year, to mix things up, it will be the Swiss Peaks 170 all the way from Grande Dixence to Le Bouveret. A big adventure in th e mountains à la valaisanne. What will I learn this time?

Structured Training, Scenic Trail

Mon, 09 Jun 2025 01:37:21 +0000

The fog was relatively thick. You were able to see where you were going, sure. But milestones, such as summits, settlements remained shrouded, panoramas denied to the crowd of runners who set out to tackle the Scenic Trail K54 in Ticino, Switzerland.

Back-of-the-envelope: energy expenditure in a multi-day footrace

Wed, 07 Feb 2024 10:40:30 +0000

How much energy do you spend on a multi-day foot race? I tried to estimate the expenditure first, using a back-of-the-envelope calculation before stumbling over a study researching exactly that. Fun with bananas.

Swiss Peaks 360, Race Reviewed

Tue, 12 Sep 2023 01:39:16 +0000

The Swiss Peaks 360 foot race is done. Finished after 5.5 days of madness, covering a distance of over 360 km, 25900 m elevation gain, 26900 m elevation loss. Deprived of sleep, but enriched with an intense experience; body fatigued, but mind inspired. Time to look back on this unique adventure in the spectacular scenery of Valais in Switzerland.

Swiss Peaks 360, Specific Period Reviewed

Sat, 26 Aug 2023 06:50:02 +0000

The specific period of training for this year’s edition of the Swiss Peaks 360 foot race is complete. Time to look back, taper, and fine-tune the preparation for the big adventure in the gorgeous mountains of Valais in Switzerland: over valleys and passes from Oberwald to Fiesch, Eisten, Grimentz, Grande Dixence, Finhaut, Morgins to Le Bouveret.

Using Strava segment efforts as benchmarks: heart rate versus running speed

Mon, 07 Aug 2023 12:15:14 +0000

How to find out whether my training is effective? A casual investigation into whether I can use frequent Strava segment efforts in order to see whether the ratio of heart rate versus speed shifted between two training seasons. The results look promising.

Swiss Peaks 360, Support Period Reviewed

Tue, 01 Aug 2023 03:44:47 +0000

What I called the support period in my preparation for this year’s edition of the Swiss Peaks 360 foot race is complete. Time to look back, assess progress, shape the last training period before the big adventure, which will bring me to the vast mountaineous landscape of Valais in Switzerland.

Progressor, Programming the Training Program

Mon, 10 Apr 2023 00:57:20 +0000

How to plan the training sessions for the weeks ahead? I hacked together a web app which allows me to do just that. The app helps me to plan the training progression according to established training principles, supporting modes such as running, hiking, cycling. Apps for the purpose exist commercially, but it was fun and instructional to roll out my own.

A computer scientist's attempt at tracking the effect of training without testing

Fri, 07 Apr 2023 08:28:27 +0000

How to find out whether the effort put into training actually increased performance? I asked myself whether there is a shortcut to testing benchmark protocols, whether in the lab or in the outdoors. As you may already have guessed, shortcuts are rare in training. But sometimes, it’s fun looking for one.

Swiss Peaks 360, Base Period Reviewed

Sun, 02 Apr 2023 08:22:59 +0000

Two weeks left in what I called the base period in my preparation for this year’s edition of the Swiss Peaks 360 foot race. Time to look back, subjectively and objectively, assess progress (or the lack thereof), and thus set the foundation for creating a more detailed plan for the upcoming training period.

Putting more C into running: trail-maniacs

Sun, 19 Mar 2023 04:51:25 +0000

In 2023, I intend to contribute more to the running community, again. The opportunity to do so presents itself through leading one of the crews in the trail running club I joined last year, the trail-maniacs, ever so aptly named.

Swiss Peaks 360, Prepping for the Next Edition

Mon, 20 Feb 2023 10:09:51 +0000

Poised to experience the Swiss Peaks 360 foot race again in 2023! An epic journey through Valais, covering 360 km and an excess of 26,000 m of vert in less than a week. One thing is certain: preparation is necessary. As a self-coached hobby-athlete, sketching the training remains up to me.

Pomodoro Timer: Prototype, Round 3

Fri, 30 Dec 2022 05:39:11 +0000

The “pomodoro technique” is a simple time management method, which requires a robust, simple-to-use timer, which doesn’t distract from the task at hand. For the third version, I constructed a plywood case to house the microcontroller, the 4-digit display, and the two buttons to control the timer.

Pub combinatorics: the joy of rediscovery

Sun, 27 Nov 2022 02:44:14 +0000

Learning is often a process of rediscovering things. I enjoyed this process recently when trying to solve a combinatorial puzzle, in the pub, in the bus, and at home. A tale of allowing myself to explore, to tinker, and to be awed by the great thinkers of long gone times.

Quick-fix: Typing ÄÖÜ on a UK Keyboard

Sun, 13 Nov 2022 07:34:00 +0000

UK keyboards, for good reasons, do not come with keys for ÄÖÜ. Here is a quick-and-dirty fix to customize the xkb symbols map, tested on on Arch Linux.

Pomodoro Timer: Prototype, Round 2

Sat, 29 Oct 2022 11:54:05 +0000

The “pomodoro technique” is a simple time management method, which requires a robust, simple-to-use timer, which doesn’t distract from the task at hand. After the first prototype with the ATmega32-based RN-Control v1.4 experimental board, I built another prototype: this time with a 4-digit display.

The Bike, Your True Sport Utility Vehicle

Tue, 13 Sep 2022 10:45:55 +0000

SUVs with four wheels? Zero sport utility, questionable utility for the climate, questionable use of limited space in cities, and on top of that a danger to pedestrians. An opinion in favour of making Switzerland friendlier for the bike, your one true sport utility vehicle.

Pomodoro Timer: Prototype with an ATmega32

Mon, 12 Sep 2022 07:35:38 +0000

The “pomodoro technique” is a simple time management method, however in my opinion completely lacks support from something essential: a robust, simple-to-use timer, which doesn’t distract from the task at hand. Thus, I built a prototype with the ATmega32-based RN-Control v1.4 experimental board.

Swiss Peaks 360, Lessons Learned

Wed, 07 Sep 2022 00:20:22 +0000

After completing the Swiss Peaks 360 foot race, it’s time to contemplate what I learnt from moving through the mountains of Valais over a distance of 360 km and a vertical gain in excess of 26,000 m, in less than 6.5 days.

Swiss Peaks 360 is a Go

Sun, 21 Aug 2022 11:10:35 +0000

This year’s challenge is approaching: Swiss Peaks 360. After recovering well from “the plague” in early July, and coming to terms with the turmoil it caused to my training, I decided already a few weeks ago: It’s a Go.

The Pandemic Wants Me, Too

Wed, 06 Jul 2022 08:11:19 +0000

Hit a roadblock 194 days into the training cycle, and 160 days after my previous post. Turns out the COVID-19 pandemic wants me, too. I am grateful, that so far, the pandemic does not seem to make me give as much as it makes others do. Nevertheless, time to reflect on the training so far. Time to poke a bit into available research on how to safely return to what all athletes want: get back out, and continue.

Exercised at home: hacking a plyo box

Thu, 27 Jan 2022 12:18:07 +0000

How to bring some hills into your home? Such to train for hiking using box step-ups when stuck at home? After surprisingly long Internet research, I finally found a compact, wooden, pretty-enough “plyo box” . Even though plyometrics wasn’t what I had in mind.

Right control key on keyboard as i3 modifier in Ubuntu 20.04

Sat, 22 Jan 2022 09:09:05 +0000

If you ever wanted to use the right Ctrl button in Ubuntu 20.04 as an i3 modifier, and struggled with xmodmap, try editing the modifier mappings directly in /usr/share/X11/xkb/symbols/pc. It’s dirty, and may fail during software update─but meh until then it appears to work.

Swiss Trail Tour, Day 3

Tue, 21 Sep 2021 03:59:54 +0000

Punishment. Today’s theme is voluntary punishment. The last stage of this footrace is framed by rain and snow. After two days of sunshine tralala, the adventure gets a new facet. Impressions from Day 3 of the Swiss Trail Tour.

Swiss Trail Tour, Day 2

Tue, 21 Sep 2021 03:30:27 +0000

The longest stage of the Swiss Trail Tour is awaiting me. Spirits are still running high, although my legs remember the effort from the previous day. How is it going to turn out today? Impressions from Day 2.

Swiss Trail Tour, Day 1

Tue, 21 Sep 2021 03:25:20 +0000

Nine months after signing up, after nine months of training, race day has finally come. Spirits are running high. I can’t wait for the start of this footrace. What does the first day have in store? Only time will tell. Impressions from Day 1 of the Swiss Trail Tour.

For One Thing Is Certain, Connie Loves Cake

Thu, 27 May 2021 12:41:27 +0000

Mid 2021. Almost 1.5 years have passed since we moved to Switzerland. Connie has seized the chance to create a new venture during challenging times, turning what could turned crisis into opportunity by starting her very own cake shop. I cannot help but write a few words on that journey.

Pursuit, a take on personal OKRs: Nine months later

Mon, 19 Apr 2021 08:23:33 +0000

In August 2020, I started using a home-made web application to track my personal OKRs: Pursuit. Nine months later, I am still using Pursuit on a daily basis. A brief review with which I hope to inspire you to work towards your own big goals, and particularly to stay present on what matters most: the journey to get there.

Swiss Trail Tour, Darth Vader on a Treadmill

Sun, 18 Apr 2021 07:07:18 +0000

What does Darth Vader do on a treadmill? Breathe, breathe, breathe. This week, I treated myself to the futuristic world of performance diagnosis: I wanted to learn more about where I am as a hobby runner, how to improve from there, and how applied science in sports works nowadays.

Thoughts on 'The Practicing Mind' by Thomas M. Sterner

Sun, 11 Apr 2021 22:52:01 +0000

Having been on a journey to increase my ability to focus for some time now, I recently read ‘The Practicing Mind’ by Thomas M. Sterner. This book emphasises process, and the importance of not getting distracted by a goal while being in the process of working towards it. Let’s review what to take out of this book.

Swiss Trail Tour, Incorporating Objective Feedback

Sat, 03 Apr 2021 23:54:06 +0000

Without feedback, you can only achieve what you already know how to do. With feedback, you can achieve what that you do not yet know how to do. I believe that feedback loops are at the core of any development. In this post, I am sharing my thoughts on incorporating objective feedback into long distance running training by visualizing data from Strava in Google Data Studio.

Swiss Trail Tour, Training Differently

Fri, 19 Mar 2021 12:43:04 +0000

After more than a decade of running, I figured it’s time to understand how training actually works. Unsurprisingly, after digging through three books on the art and science of exercise, I have changed how I train for the Swiss Trail Tour this year. Maybe such research will change your training, too.

A formula for converting pace from min/mile to min/km in Google Spreadsheets

Thu, 04 Mar 2021 10:49:15 +0000

If you are a runner and desperate for a quick-and-dirty formula you can use in a Google Spreadsheet to convert running pace from minutes per mile into minutes per kilometer, this nerdy post will give the formula to you.

Thoughts on 'Pragmatic Thinking & Learning' by Andy Hunt

Sat, 20 Feb 2021 04:06:21 +0000

Having been influenced by the ‘The Pragmatic Programmer’ a long time ago, I recently re-read another book from one of the authors, called ‘Pragmatic Thinking & Learning’. The book caught my interest since thinking and learning are absolutely essential in my line of work, and learning is a great enjoyment outside of work for me. Let’s review what the book is good for.

Swiss Trail Tour, Beginning or Comeback?

Sat, 13 Feb 2021 10:04:36 +0000

Having signed up for the Swiss Trail Tour in September, I am wondering whether this is a comeback to ultra running, or rather the beginning of something else? Either way: why do this, and how to prepare for three days of trail running─and hiking─a total distance of 103 km and 6000 m elevation gain?

Thoughts on 'Focus' by Daniel Goleman

Sun, 07 Feb 2021 10:59:23 +0000

One of these rare moments: I finished a book. Called “Focus: The Hidden Driver of Excellence”. Reading it to the end is an accomplishment by its own, as I had started this book years ago but then put aside for a reason I can no longer remember. Although it’s clear that, back then, my focus must have moved on to something else. Reflections after finishing a book on what is an essential topic in the information age.

Pursuit, a take on personal OKRs

Sun, 27 Dec 2020 12:01:34 +0000

The year 2020 taught me again how powerful good habits are, once established. How important it is to continuously do the many small steps that are required to achieve goals, from smaller to bigger goals. I wrote an app─nicknamed “pursuit”─which helps me to formulate, commit, and measure the progress towards goals. I will share the ideas with you, may it inspire you to progress towards your goals in 2021.

Visualizing Strava activities with BigQuery and Google Data Studio

Fri, 25 Dec 2020 04:53:48 +0000

How to load Strava activities into Google Cloud BigQuery and visualizing the activities with Google Data Studio? This article is for (hobby) athletes interested in taking a walk through the Strava API, Google Cloud Platform and Google Data Studio; showing how to gain the freedom to explore and visualize the data you have been sweating for over years.

A not-so-serious SARIMA forecast for running in 2020

Thu, 25 Jun 2020 10:59:25 +0000

Just for fun: what happens when you fit a SARIMA model (using statsmodel) over past Strava running activities in order to predict remaining running distance in 2020? Not much happens beyond the nourishment of my interest in predicting time series.

Some hills, finally

Sun, 21 Jun 2020 06:12:38 +0000

In the past years, finding some way to train hill running prior to races was difficult for me. I tried office staircases but they were boring and the air was dry and stuffy, so I failed to follow my training plan. Ever since moving to Switzerland, this is no longer a problem. I ran some statistics over activity data pulled from Strava, and the results are promising.

A computer scientist's diagram of the systems that turn macronutrients into energy for the muscles

Mon, 01 Jun 2020 05:33:29 +0000

How do the macronutrients we eat─carbs, fat and protein─turn into energy that the muscles can use as fuel? How to answer this question without failing to see the forest for the trees? In this post, I am trying myself at a high-level abstraction based on the book Lactate Threshold Training by Peter Janssen.

A computer scientist's diagram of heart and lung supplying the muscles with oxygen

Mon, 25 May 2020 12:53:25 +0000

What happens if a computer scientist tries to understand more about the heart and lung supplying the muscles with oxygen? The computer scientists applies graph theory. Out comes the flow conservation principle, and─woosh─there’s a diagram relating cardiac output, oxygen consumption and oxygen intake.

The sublinearity of spaced repetition learning

Sun, 24 May 2020 09:53:14 +0000

Spaced repetition learning (SRL) is a technique to memorize a large amount of items, such as vocabulary when learning a foreign language. In this article, I am writing about a primary benefit that I see in SRL: under the assumption that SRL is effective, I claim that SRL is also efficient; the amount of repetitions grows sublinearly in time and new items to learn.

Factfulness, Straight Line Instinct & World Population

Sun, 19 Apr 2020 03:30:41 +0000

“Factfulness” is a fantastic book, remaining as current as it was when I purchased it. It gives us “ten reasons we’re wrong about the world and why things are better than you think”. Today, I am going to have a look at the Straight Line Instinct and the forecasted world population growth.

Thoughts on Model Thinking: a smörgåsbord

Sun, 05 Apr 2020 08:46:49 +0000

A review of Scott Page’s Model Thinking course, which has been overall entertaining, inspiring, informative albeit at times a bit repetitive when going through arithmetics. If you are interested in trying to make sense out of the complex world around you, this course might be for you.

Modeling Swiss basic health insurance

Sun, 08 Mar 2020 10:57:35 +0000

In this article, I am reverse-engineering the Swiss healthcare system, with the help of some maths and diagrams. In particularly, I am looking at the impact of the deductible when buying a basic insurance policy. How much difference does the choice of deductible make?

Hello, Switzerland

Thu, 05 Mar 2020 13:11:47 +0000

In a typical programmer’s unimaginativeness, let’s print out a localized version of the few words that everyone starts with: Hello, Switzerland. After almost six years, a step into a new country again. It is time for a thought abroad.

London ─ Towards British Citizenship

Sat, 29 Feb 2020 14:12:49 +0000

The fifth post on my “London ─ Living through history” series • touching modern British history • about Brexit • on gaining British Citizenship • let us maintain, build, and rebuild bridges.

London ─ Impressions twenty-four-seven

Sun, 26 Jan 2020 09:08:19 +0000

Why London left a lasting impression • architecture, accumulated over millenia • where old meets new, in one place • why it is worthwhile to look at the same place at different times • where old meets new.

London ─ Path to the outdoors

Wed, 01 Jan 2020 09:39:42 +0000

How to find the outdoors while living in London • London has surprisingly many green spaces • thanks to Paul New, Cliff King, Rachel Dench • thanks to the London Social Runners • on England’s history of volunteering • you cannot avoid the air pollution • you often have to stay on public footpaths • historic sightseeing in run-by mode.

London ─ As far as the eye can see

Sat, 28 Dec 2019 15:05:08 +0000

London is large enough to accommodate the population of Switzerland • speed flatmating is not for me • receiving solace from Thomas Edison • London is more than what you can see on the tube map • Nappy Valley • between the Commons • some fences are pointless • houses, as far as the eye can see.

London ─ Living through History

Fri, 22 Nov 2019 12:01:39 +0000

I moved to London from Stockholm at the beginning of April 2014. I left university life behind and moved on. Back then I had no idea how long I would live in London. And even less of an idea, what changes there were in store for me. I am now soon leaving London─although only time wil tell for how long. It seems only appropriate to add some closing thoughts on this chapter.

UK taxes for dummies, a visual approach

Thu, 14 Nov 2019 12:57:03 +0000

In the UK, I was recently asked by someone how much money would remain from their income after taxes. While I could give a pretty good estimate, I discovered I had actually no idea how the net income is actually computed. None of the documentation I found was easy to understand. However, I can read maths. And I can look at pictures. So here’s a visual approach to a net income calculator for the UK, for dummies like me.

Walnut bread: I'll be back

Sun, 27 Oct 2019 08:52:55 +0000

A second, brief post on my quest for becoming independent from commercially sold bread. Where I got tips for free (and then dutifully paid for merchandise), and where to get all the flour you cannot find in your UK supermarket.

Baking bread took me seven years to learn

Sun, 08 Sep 2019 03:50:24 +0000

But not for the reasons that you would imagine. I just failed to realize bread making is neither time consuming, nor particularly difficult. For those who are not satisfied with the bread available to purchase, and those who don’t want to wait seven years to find a solution, let me write this down…

The staircase up Mount Everest, an office workout

Sat, 27 Jul 2019 02:30:34 +0000

No need to climb the ladders up Mount Everest if you have the staircase of an eleven-floor office block to scale. This staircase is going to replace the hill training for me in the months to come. Around 8890 meters over 2068 floors in 17 weeks. Let’s see how difficult that is.

Forecasting Ozone levels in London

Sun, 30 Jun 2019 08:08:43 +0000

How high will be ozone levels in London next year? I have looked into the London Average Air Quality dataset in order to see patterns and to produce crude estimates. Here is what I learnt about ozone and discovered about roadside and backgroudn ozone levels in London.

Statistics tell you when to stop practicing

Thu, 30 May 2019 13:33:21 +0000

Assume you are practicing for an exam. You could spend all your time left until the exam practicing (possibly too much), or you could spend almost no time practicing (likely too little). So how do you know when enough is enough? When can you stop practicing and yet be confident that you will pass the exam?

Applying Machine Learning to Strava activities using BigQuery ML

Sat, 06 Apr 2019 07:33:28 +0000

Today, I’ll demo how to train a logistic regression model in BigQuery ML. That is Machine Learning models written in SQL, and executed in BigQuery.

Inspecting air pollution data from OpenAQ using Colab, Pandas, and BigQuery

Sat, 09 Feb 2019 09:51:06 +0000

OpenAQ is publishing real-time air quality data from around the world to BigQuery. Today, I have poked around in the dataset to inspect air quality from many places of the world.

Running the North Downs Way─XNRG Pilgrim's Challenge 2019

Tue, 05 Feb 2019 12:26:57 +0000

Postcard-Britain! The 66 mile race course took me from Farnham over the very pretty & snow-covered North Downs, until the snow subsided and was replaced by mud, past Box Hill until Redhill and back the next day. This post is about the madness that is required to enjoy such an adventure, and the odd things that you might encounter.

Runsightseeing: Thirteen London parks in a day

Sun, 16 Dec 2018 09:57:30 +0000

London has so many parks. Today, I managed to run and visit thirteen of them on an extended sightseeing trip, discovering various artwork while doing so, and passing through many different neighbourhoods. I failed to complete the XNRG Santa Virtual Ultra Challenge, but I regret nothing.

Running the Ridgeway─Druid's Challenge 2018

Mon, 26 Nov 2018 09:51:04 +0000

A comeback to the world of ultra-running. This time, I ran (and walked) the Ridgeway from Tring to Swindon in three days as part of the XNRG Druid’s Challenge.

What probability theory tells you about starting on time

Sat, 06 Oct 2018 13:52:01 +0000

Whether you are an event organizer waiting for participants to turn up or whether you are a bus driver waiting for passengers running to catch the bus, there is a dilemma: if you are so kind and wait for everyone to arrive, you make everyone else wait. Let’s explain the dilemma with probability theory.

Analysing Strava activities using Colab, Pandas & Matplotlib (Part 4)

Wed, 04 Jul 2018 07:46:03 +0000

How do you analyse Strava activities—such as runs or bike rides—with Colab, Python, Pandas, and Matplotlib? In my fourth article on this topic, let’s invite scikit-learn and NLTK to the party, and apply some Machine Learning.

Analysing Strava activities using Colab, Pandas & Matplotlib (Part 3)

Fri, 15 Jun 2018 15:37:24 +0000

How do you analyse Strava activities—such as runs or bike rides—with Colab, Python, Pandas, and Matplotlib? In my third article on this topic, I am demonstrating how to visualize the data in different ways.

Analysing Strava activities using Colab, Pandas & Matplotlib (Part 2)

Fri, 01 Jun 2018 14:26:31 +0000

How do you analyse Strava activities—such as runs or bike rides—with Colab, Python, Pandas, and Matplotlib? In my second article on this topic, I am demonstrating how to group and aggregate the data in many different ways.

Analysing Strava activities using Colab, Pandas & Matplotlib (Part 1)

Mon, 28 May 2018 11:57:33 +0000

How do you analyse Strava activities—such as runs or bike rides—with Colab, Python, Pandas, and Matplotlib? In this post, I am demonstrating how to get started, and will give you a taster of what is possible with this state-of-the-art technology for data analysis.

Run to work—Notes on kilometer 124

Mon, 07 May 2018 13:50:08 +0000

In the last five weeks: 15 run-commutes completed, 124 kilometers logged, £43.50 saved on public transport. The trick? Always having my kit ready the night before.

Misleading infographics: How Not To Bubble Chart

Sat, 07 Apr 2018 10:46:59 +0000

I discovered a misleading infographic on mortality cause by gender in the OECD report “Health at a Glance 2017” while working on a course assignment. A few notes on how not to do bubble charts.

Run to work, revisited

Sat, 31 Mar 2018 09:31:51 +0000

With my recent move to East London, running to work has become a topic again. Surprisingly as it may sound, getting the logistics right is the hardest part. Here is my plan on my comeback to run-commutes.

A Walk in The Woods: 2017 Edition of Wendover Woods 50

Sun, 26 Nov 2017 03:16:52 +0000

After having watched the second half of the film adaptation of Bill Bryson’s A Walk in The Woods, I can’t help but spot the remote similarities: an ambitious challenge, an uncompleted journey through the “woods”, and a literary attempt to explain the adventure. In my case, I gave up during a footrace of 50 miles and about 3000 m elevation gain, known in the runner’s world as Wendover Woods 50.

Memories from University: Teaching the Computer to play Connect Four

Thu, 26 Oct 2017 14:06:50 +0000

How do you teach a computer to play games? I took a classic brute-force approach along with some techniques to make the search for a good move faster. Can you beat the machine?

Lakes in a Day: I've dunnit, finally

Sun, 08 Oct 2017 13:38:49 +0000

Finally my dream has come true, even though things were different than imagined: A race report of Lakes in a Day, traversing the Lake District in 50 miles with 4000 m ascent.

North of the Arctic Circle: Hiking adventures in Sweden

Wed, 26 Jul 2017 13:46:51 +0000

My dream of returning to Northern Sweden for some hiking came true this year. Streams and lakes, puddles and pools, snow and ice, mountains and valleys; orienteering, pathfinding, river crossing, wild camping. Fabulous views rewarded the efforts I put in.

Running the XNRG South Downs Devil's Challenge 2017

Tue, 02 May 2017 14:46:31 +0000

It’s bank holiday weekend in the UK. What better thing to do than joining a bunch of nutters for a three-day foot race from Winchester to Eastbourne, covering 156 kilometers and many hills? I could not come up with a better idea, so here is how it went.

Garden of England: Running from Ashford to Canterbury

Sat, 15 Apr 2017 12:44:14 +0000

This Saturday, I decided to explore the North Downs Way between Wye and Canterbury. A trip report touching many things: navigating with phone and compass instead of maps, public footpaths and plough teeth, explosives and barbed wire, parking lots in unexpected places, and oceans of bluebells.

Three Years in the United Kingdom: Need Candles in the Dark

Wed, 29 Mar 2017 14:24:10 +0000

Exactly three years after my arrival in London, the UK Government has triggered article 50. The Brexit drama continues, with decision-making in the dark being a defining part of the play. It is time for a few personal reflections from a “first-row seat”.

Missing Maps: Use Your Phone for the Better

Mon, 13 Feb 2017 14:50:24 +0000

The opportunities created by the advance of technology and the efforts of people are amazing. In this post, I’ll show how to take advantage and use the Mapswipe App as a first step to gain valuable insights for NGOs operating in places of the world for which there is no proper map yet.

Country to Capital 2017: Resurrection

Sun, 15 Jan 2017 06:11:19 +0000

The annual Country to Capital race takes a few hundred enthusiasts from Wendover to London Paddington in what is said to be the opener of the ultra marathon season. There are stark contrasts between country and capital, and it was interesting to observe the gradual transition.

Utility theory and pedestrian behaviour in London

Mon, 09 Jan 2017 10:43:30 +0000

A not-so-serious attempt at explaining pedestrian behaviour in London using utility theory. Ever wondered why certain pedestrians jump so readily in front of passing lorries? Ever wonder why some are keen to collide with approaching cyclists? Sorry, I don’t have the answer, either. But I am still curious. And in a mood to rant. Just a little bit.

How data can assist us in forming good habits

Sat, 17 Dec 2016 12:42:20 +0000

Habits are an important key to success. But how do we establish a habit? How do we know whether our perception aligns with reality? How do we decide about the next change to make? Did we succeed? I want to know. A reflection on habits, insights from data using running as an example.

Wendover Woods 50: First Ultramarathon

Sun, 27 Nov 2016 04:43:47 +0000

November. Saturday. Dark, foggy, chilly. These were the conditions for around 200 loopy runners to set off on a loopy five-lap course through the small, pretty & hilly Wendover Woods. 50 miles later, and after arduous 3000m of ascent, I got a fairly thorough taster lesson in ultrarunning.

Missing Maps: Putting People on the Map

Wed, 23 Nov 2016 13:40:23 +0000

There are places on our planet where people live but there is no map. How are NGOs like Médecins Sans Frontières (MSF) supposed to do field work if they don’t know where people live, how many, how to get there? The Missing Maps project is addressing the issue via crowdsourcing. I gave it a try, and here’s what I think.

Enham Alamein: Andover Trail Marathon

Sun, 04 Sep 2016 08:13:50 +0000

This weekend, I traveled down south from London to participate in the newly setup Andover Trail Marathon. The start and finish was in Enham-Alamein. A place that caught my attention – El Alamein? Historical and personal battles.

From Stockholm to Oslo by Bike

Fri, 29 Jul 2016 10:31:07 +0000

Bike touring, wild camping, ferry rides, sun bathing, bike packing, and more. A recount of a loosely planned bicycle trip that brought me another time across Sweden, and this time also a tiny bit of Norway.

The Hitchhiker's Guide to the Giants Head Marathon

Sat, 02 Jul 2016 12:44:15 +0000

On the last weekend in June, I ran (and walked) the Giants Head Marathon in West Dorset. Well-organized, welcoming, laid-back, and not so simple to get to. Highly recommended.

Without Captain, Course, Destination: Sailing Away

Tue, 28 Jun 2016 15:58:10 +0000

Several months ago, I concluded a post about the EU referendum with “Sail away. A thought abroad”. I am thoroughly disappointed that the UK actually did. Or half of it? The ship has left the harbour, without captain, without course, without destination, and most disturbingly with a deeply divided crew.

Herräng, en resa till Herräng

Mon, 23 May 2016 17:06:13 +0000

Några veckor kvar inför nästa resa till Sverige. Den här gången på sommaren. Vilket är ju inte den värsta tiden att åka dit. Jag är mycket nyfiken på danslägret i Herräng, vilket är välkänd bland dansarna i Swingvärlden.

Welcome to Scotland, Revisited

Sat, 14 May 2016 09:15:31 +0000

Back from an extraordinary hiking trip to Scotland. Soaring temperatures, not a single drop of rain, few midges, outstanding panoramas were just some of the highlights of my second multi-day hiking adventure into the West Highlands.

To run or not to run – that is not the question

Sun, 24 Apr 2016 13:14:04 +0000

At the end of last year, I had decided to spend more time outside of London to discover the rest of the UK. In order to make that happen, I booked a few races in various parts of England. Today, on the weekend of the 400th anniversary of Shakespeare’s death, this brought me to Stratford-upon-Avon.

Air Pollution – Green, Yellow, Red: Toying with CleanSpace

Fri, 25 Mar 2016 05:45:58 +0000

Got the CleanSpace tag delivered. It is a RF-powered, portable device measuring carbon monoxide concentration. I spent a few days playing with it, and sharing my first impression here. Ultimately, I want to know whether the data can help foster change to the better.

Energy from Thin Air: Measuring Air Pollution with CleanSpace

Thu, 17 Mar 2016 14:02:55 +0000

Let’s face it. Air quality in London is quite poor. You don’t need technology to notice. As soon as you reach the country side, the difference is usually very apparent. I will soon get hold of an active sensor that transfers carbon monoxide readings to my phone in real-time. Interesting: the sensor is powered only from energy harvested from wireless and broadcast networks. Energy from thin air!

Ice skating in tailwind

Sun, 10 Jan 2016 13:37:44 +0000

Great timing. A wave of cold temperature and clear skies comes to Sweden precisely when needed. But if it weren’t for the logistics, the wind could have made ice skating impossible. A story in pictures on what the dark and cold winter in Sweden had to offer.

Europe – Story of a Migrant

Sat, 28 Nov 2015 12:05:53 +0000

No, this is not a story about a refugee even though certainly many could be written. Instead, it is a story about a migrant within the European Union. A story that should make UK citizens think twice. A story against reactionary and nationalistic tendencies.

Quantify this: Running

Fri, 13 Nov 2015 14:05:23 +0000

It’s easier than ever to track your mileage in running, cycling, and many other activities. But why would one do that? For the present self to celebrate past accomplishment?. Or to post it online here for promoting one’s virtual self? No. I want to track running mileage in order to adjust my course and correlate exercise with race performance.

San Francisco Sunday Swing: Lindy in the Park

Sun, 18 Oct 2015 19:42:25 +0000

What a friendly welcome of the local Swing dancing community in San Francisco! I’m saying thank you and recommend the following to my fellows in London – should you ever visit San Francisco, then Lindy in the Park is a place to go to.

Getting lost in a marathon: an extra mile for free

Sun, 02 Aug 2015 11:01:49 +0000

As if the race wasn’t long enough on its own, some runners did not pay enough attention and had to run the extra mile in the Vanguard Way Marathon, a nice and challenging race on scenic trails south of London. A humoristic take on how to get more out of the race than you paid for.

Run to work: Review of first year

Thu, 16 Jul 2015 12:12:30 +0000

Run to work statistics: 41 commutes, over 200 km distance covered, 17 hours spent on exercise, around GBP 86 saved on public transport, not so fresh air, and a ridiculous number of trolleys avoided by not having to go through one of London’s busiest train terminals.

Across the Alps by Bike

Mon, 15 Jun 2015 04:47:39 +0000

A journey through valleys, villages and across mountain passes, through sunshine, rain, and thunderstorm: in this year’s mountain bike trip, we crossed the Alps from Oberstdorf in Germany to Lake Garda in Italy.

Through the Normandy to Paris by Bike

Wed, 27 May 2015 14:43:08 +0000

What started as a joke turned into reality on a bank holiday weekend: A bicycle ride from London to Paris. Well, to be exact, we skipped the part from London to the channel and started in Dieppe.

50 km of Wales in a Day: Big Black Mountains Challenge 2015

Mon, 18 May 2015 12:38:59 +0000

Panoramic views on a scenic route through the Black Mountains in Wales. This challenge, organized by the Longtown Mountain Rescue Team, was worth every step that was needed to complete the 50 km hike. We arrived tired, but happy before sunset.

Cycling in London

Mon, 13 Apr 2015 13:24:08 +0000

On the topic of cycling in London: much has been written, and more will be written. That is because it is a complicated matter. This is a brief and incomplete view on the upsides, the downsides, and the quirky aspects of cycling in London.

Cardboard cut-out: a solution for the sliding piano pedal problem

Sun, 22 Mar 2015 11:14:15 +0000

The pedal of the electric piano in my room keeps sliding and slipping away under my foot. A well-known issue. Placing the piano on a large piece of cardboard fixed this: a cut-out of the right size is now keeping the pedal in place.

Long distance ice skating on Siljan: Old places, new adventures

Fri, 20 Feb 2015 12:18:42 +0000

The ice conditions and the weather in Stockholm being far from ideal for ice-skating, we travelled all the way up to Lake Siljan in Dalarna, Sweden. An essay on the wonders of long-distance ice-skating, a winter activity as fantastic as well as little known outside the Nordic countries.

Train to Paris

Thu, 25 Dec 2014 13:13:07 +0000

It was my second time in France. After exploring the countryside in the Auvergne a decade ago, this time I visited the capital over a weekend while travelling from London to Munich by train and by bus. A mixed story about discovering Paris by foot.

Svenska utanför Sverige – hur gör man då?

Fri, 14 Nov 2014 14:43:00 +0000

Man brukar säga att det är mycket lättare att lära sig ett främmande språk när man befinner sig i landet där språket talas än om man befinner sig utomlands. Angående svenska som främmande språk får jag nu ingå kompromisser eftersom jag inte längre bor i Sverige. Kommer jag att glömma bort allt som jag lärt mig? Helst inte.

Bletchley Park and the rebuilt bombe

Sat, 04 Oct 2014 14:51:04 +0000

A visit to Milton Keynes gave me a brief look into former codebreakers’ life at Bletchley Park during World War II. The exhibition also featured a rebuilt exemplar of the bombe, an electromechanical machine that played a role in breaking the code of the Enigma. I got fascinated for several reasons.

Hiking in the Sierra Nevada: Boulders, Bears, and Giant Sequoias

Sat, 20 Sep 2014 18:18:51 +0000

It was my first four-day hiking trip in the wilderness of the Sierra Nevada in the Sequoia National Park (California). This is a recount of my experiences and a descriptions of the lessons I learnt while carrying my backpack with food and shelter over segments of the High Sierra Trail.

Saatchi Gallery: What is this made of?

Tue, 26 Aug 2014 13:51:12 +0000

A friend recently showed me this place. I am posting no more than this: have a look at Saatchi Gallery in London and find out. Guess first what it is. Find out later.

Eastbourne via Beachy Head towards Seven Sisters

Mon, 25 Aug 2014 12:11:44 +0000

Spending a day at the Channel near Eastbourne, escaping to more scenic running routes than London can offer. Wind and rain. The weather forecast calls it “heavy drizzle”. Impressive.

Lightshow in London

Sat, 23 Aug 2014 15:42:02 +0000

The deserted City of London on Saturday. Almost empty. Brilliant colors and stark contrasts on a unique day of sunshine and rainfall – a few pictures.

Scotland, Let the Sky Fall

Sun, 17 Aug 2014 01:02:13 +0000

A recount of a hiking trip into the wilderness of Scotland: on ex-hurricanes and their effects, suicidal drivers, famous spots from the literature and the movies, a town nicknamed Lang Toon and on the festival time in Edinburgh.

Run to work: Review of first month

Thu, 31 Jul 2014 15:13:38 +0000

Time to have a look how my experiment worked out in the first month. Running to work has lived up to my expectations and has never yet failed to lift my spirits. There is room for improvement, but the 14 runs totalling in more than 70 km were worth every kilometer. Here are the few lessons learned.

Bouldering the Vauxwall in Vauxhall

Tue, 29 Jul 2014 15:16:11 +0000

Finally gotten around to check out Vauxwall, a newly opened bouldering centre in London. We were pleasantly surprised by finding nice bouldering areas in a few railway arches near Vauxhall. Even better, we had the place basically for us – no one else there, what a luxury.

It's a long road: Marathon through Hyde Park

Sat, 28 Jun 2014 15:36:49 +0000

How is it to run a marathon? Having asked me this question often enough, I decided to settle the matter and run laps in Hyde Park until I either give up or finish. No starter fees. Without time limit. Lessons learnt from a long journey.

Motion Segmentation of RGB-D Videos via Trajectory Clustering

Sat, 21 Jun 2014 03:08:53 +0000

Persistence paid off. The little, remaining work on my Master’s thesis at KTH is finally completed. I can hardly remember touching a subject at university that was as demanding and as satisfying as the research on how to segment moving objects in videos taken by a RGB-D camera. Thanks to everyone who helped me with this mission.

Bike to work? Run to work.

Thu, 19 Jun 2014 13:02:23 +0000

It’s 5.5 kilometers for me to my workplace in London. I took my running shoes instead of public transport. And I will do this again. The idea is not new, though – and people are already shouting on the web for making running to work tax-deductible. But it’s not tax that matters. It’s trading commuting time against exercise.

No umbrella needed: Riverside impressions of London

Tue, 10 Jun 2014 14:04:14 +0000

Impressions from a riverside walk with a friend. This is “proof” for all my friends who had expressed doubt on the weather in London before I left to live there. Besides, I don’t even have an umbrella.

Mountain View: a cyclist's point of view

Mon, 12 May 2014 21:22:48 +0000

Mountain View in California is a place where cars are the primary means of transport. But I was told that biking is an option, too. So, I tested getting around with a bike. Here is a short review.

Preview: Motion Segmentation of RGB-D Videos via Trajectory Clustering

Sat, 10 May 2014 20:24:32 +0000

Humans are quite good at detecting motion. How about machines? Can computers automatically segment objects in videos? I dedicated my Master thesis to a particular variant of this question. Here are a few videos as a preview.

No cars for students in Cambridge

Fri, 25 Apr 2014 16:21:20 +0000

Cambridge is a bicycle-friendly city. And as I have learned recently, students at Cambridge University are usually not allowed to keep and use cars.

Fixing a Shimano EF50-8R bicycle shifter

Mon, 21 Apr 2014 03:50:59 +0000

For some reasons, the front shifter of my bicycle stopped working properly. Time to take a screwdriver and see how the shifter actually works.

Goodbye, Sweden. Goodbye.

Wed, 12 Mar 2014 09:10:19 +0000

Everything has an end. Such has my student life in Stockholm. The last days give me a chance to sum up my roughly twenty months in Sweden.

Åland – Ice-skating in Finland

Wed, 22 Jan 2014 12:55:16 +0000

From Sweden over the Baltic Sea to Åland in Finland for an afternoon of ice-skating. Waiting for us were beautiful frozen fjords. How come so few students are interested in this hobby?

Skridskoglädje på Tämnaren

Mon, 20 Jan 2014 11:57:15 +0000

Äntligen var det dags att sätta på sig skridskorna. Tillsammans med klubben gick det på en solig lördag norrut från Stockholm för att åka skridsko på Tämnaren, Upplands största insjö. Den mörka årstiden lyser verkligen upp när isen lagt sig. På riktigt.

Programmer-friendly German keyboard layout on GNU/Linux

Tue, 07 Jan 2014 09:20:39 +0000

German keyboards are usually pretty annoying for programming. Mapping the third-level of the buttons D, F, C, V to {, }, [, ] places the curly braces and brackets at more convenient locations without destroying much of the benefits of a German keyboard.

Dunedin's Finest View: Harbour Cone

Sat, 07 Dec 2013 22:42:35 +0000

The name says it: Harbour Cone is a cone-shaped hill on the Otago Peninsula in New Zealand. While most tourists pay for a tour to see penguins and albatroses, I opted for the cheap variant using a regular bus and regular hiking boots.

Among the Clouds – Roys Peak

Sat, 07 Dec 2013 21:57:32 +0000

Just when reaching the summit, a gap in the clouds allowed for a stunning view from Roys Peak in New Zealand: blue lakes, green vegetation, snowy mountains. A report from a moderate hike with an above-the-average return.

Case study: when average speed matters

Wed, 20 Nov 2013 10:42:37 +0000

This case study shows the effects of acceleration, top speed, deceleration on total travel time on short distances at the example of Transrapid in Shanghai. Bottom line: it is the average speed that matters, not the top speed. Groundbreaking result … no! But it is an illustrative example with concrete numbers that shows why reporting top speeds creates illusions.

Recursive circle packing with PostScript

Fri, 18 Oct 2013 10:56:01 +0000

Ten lines of PostScript are sufficient to draw a pretty self-similar pattern constructed by packing circles into circles.

A runner's self-experiment: Lidingöloppet 2013

Sun, 29 Sep 2013 12:41:56 +0000

The annual racing series on Lidingö is extremely popular and was booked out way in advance this year. Out of curiosity (and because I succumbed to the excellent marketing), I took part amongst thousands of others in the 30km race on Lidingö. Here is a review of the event.

Akka from Kebnekaise

Sun, 08 Sep 2013 12:46:34 +0000

A wonderful journey through Sweden. Great weather conditions. Kebnekaise, Sweden’s highest mountain called. A story both with pictures and with words.

Zwischenbericht von der KTH: Über Versuchskaninchen, Double-Degree, Kurswahl, Nerdvokabular und den Polarkreis

Sun, 01 Sep 2013 04:40:45 +0000

Den gibt es nur auf deutsch: meinen Bericht vom ERASMUS-Jahr im Rahmen des neuen Double-Degree-Studiums zwischen den Informatikfakultäten der Technischen Universität München und der Königlich Technischen Hochschule Stockholm.

Across Sweden from Kungshamn to Stockholm by Bike: Day 5

Thu, 22 Aug 2013 13:38:38 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. Here is a report about the last day – from Torshälla to Stockholm.

Across Sweden from Kungshamn to Stockholm by Bike: Day 4

Thu, 22 Aug 2013 13:06:09 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. Here is a report about the fourth day – from Mullhyttan to Torshälla.

Across Sweden from Kungshamn to Stockholm by Bike: Day 3

Thu, 22 Aug 2013 13:06:05 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. Here is a report about the third day – from Mariestad to Mullhyttan.

Across Sweden from Kungshamn to Stockholm by Bike: Day 2

Sun, 11 Aug 2013 14:52:29 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. Here is a report about the second day – from Vänersborg to Mariestad.

Across Sweden from Kungshamn to Stockholm by Bike: Day 1

Sun, 11 Aug 2013 14:51:46 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. Here is a report about the first day – from Kungshamn to Vänersborg.

Across Sweden from Kungshamn to Stockholm by Bike

Sun, 11 Aug 2013 12:46:20 +0000

Across Sweden with the bike from the west coast to the east coast? I have tried my luck. In a diary-style series of articles I will describe some of my experiences during the five days of biking In the hope that it might benefit others with similar ideas!

Von den Blauen Bergen

Sun, 28 Jul 2013 13:31:22 +0000

Fantastic view over the Alps from Halserspitze on the border between Austria and Germany. The mountain is only for the experienced and surefooted. Wildbad Kreuth at the foot of the mountain can be comfortably reached from Munich by train and bus.

Hirschberg: Bike and Hike

Sat, 27 Jul 2013 15:24:29 +0000

Roundtrip: Tegernsee - Kreuth - Hirschberg - Bad Wiessee - Tegernsee. This mountainbike trip was different from previous ones. With the weather conditions permitting, we planned our route just in time. The roundtrip went astonishingly well.

Hiking to Speer: Meeting the Nothing

Sun, 21 Jul 2013 16:07:45 +0000

A hike with phenomenal company lead from Amden to the top of the Speer mountain in Switzerland. Up there, thick clouds were hanging on one side of the long mountain ridge like an attempt to illustrate the Nothing from The Neverending Story by Michael Ende. A bath in Lake Walen topped off the hike.

Munich-Zurich by Bus includes a Ferry Ride

Sun, 21 Jul 2013 15:45:39 +0000

Interesting weekend trip from Munich to Zurich. Hitchhiked with a bus. And got an unexpected ferry ride over Lake Constance.

Lesson at Hörsaal 13

Wed, 17 Jul 2013 17:35:16 +0000

Lesson for a TUM student: a good Bavarian bite and drink at Hörsaal 13 on TUM campus Weihenstephan. “Hörsaal 13” translates to “Lecture Hall 13” but is in fact a pub with an attached beer garden – German sense of humor? Anyway, I conclude: definitely one of the better beer gardens.

Old places, new hikes – Geierköpfe

Wed, 17 Jul 2013 17:17:06 +0000

Recommendable hike close to the German-Austrian border. Starting at Musteralm at Plansee, remembering old times, then hiking up to two summits called Geierköpfe, crossing the rather exposed ridge from the western summit to the eastern summit. Enjoyable view on Zugspitze. Back the same way.

Managing encrypted devices with LVM on top of LUKS with luksctl

Mon, 10 Jun 2013 14:00:51 +0000

Start small: my first Arch Linux package submitted to the AUR. luksctl manages (portable) LUKS-encrypted devices with a logical volume manager on top of it. Profiles control how the devices are (un)locked, the logical volumes (de)activated, and the filesystems (un)mounted with a single command. Details are found at luksctl on Bitbucket.

Benchmarking Google's Speech Recognition Web Service

Fri, 24 May 2013 04:08:47 +0000

Curious: how far can we push Google’s speech recognition web service that is used in Chrome 25+ for speech input? I measured the word accuracy of the service on the TSP speech dataset that consists of recordings of the Harvard sentences in order to get the picture.

Asus Xtion Pro Live – First Impressions

Wed, 22 May 2013 15:08:43 +0000

It is now a couple of years since affordable depth cameras have entered the market. Out of a developer’s perspective, the Asus Xtion Pro Live seemed to be better suited for development than the XBOX 360 Kinect. I still think so. Here are my first impressions gained when working with the Xtion in a university project.

Sehnsucht nach Ferne – Zufrieden in der bayerischen Heimat

Wed, 22 May 2013 14:20:14 +0000

Das Interview für abi.de ist nun schon ein paar Wochen alt, aber erst jetzt ist mir aufgefallen, wie die Überschrift und der erste Satz im Zusammenhang klingen. Frei nach: in der Welt zuhause, in Bayern daheim.

Using Google's Speech Recognition Web Service with Python

Wed, 22 May 2013 08:47:56 +0000

Google powers a mostly undocumented web service for speech recognition. The web service accepts audio data and returns a transcription. Here is a way to communicate with the web service via HTTPS POST and Python.

Review of the Visualization Course at KTH: A Matter of Trust

Fri, 17 May 2013 07:15:20 +0000

When trusting the students is a good idea: a review of the project-based visualization course (DD2257) given by Mario Romero in spring 2013 at KTH. The projects presented by the students exceeded my expectations by far – but why?

Sun and Ships on a Saturday in Stockholm

Sat, 11 May 2013 15:56:47 +0000

Stockholm shows its finest side whenever it is sunny. By coincidence, a particular Saturday in spring this year was a lot about ships — ships and their stories.

Speech Input in Google Chrome: x-webkit-speech

Wed, 08 May 2013 11:33:47 +0000

Google Chrome 25+ features a nice extension for speech input, which is enabled by adding the x-webkit-speech to text input fields. I put it into action. How well speech input actually works depends heavily on what kind of words you use, though.

Clustering Crash Simulation Data with LLCA

Fri, 12 Apr 2013 10:43:09 +0000

Four longitudinal chassis beams of a Chevrolet pickup truck. The nodes of their corresponding finite element model shall be partitioned into clusters such that the nodes within one cluster show similar behaviour in a row of car crash simulations. The question: is the local clustering approach (LLCA) applicable? A summary of a research project.

German PC keyboard layout in Mac OS

Thu, 11 Apr 2013 08:12:08 +0000

For those like me who cannot switch easily between different keyboard layouts: How to use the German PC keyboard layout in Mac OS? This recipe worked for me: www.nullpointer.de/stuff/keylayout

Denmark Revisited – Back after Thirteen Years

Wed, 10 Apr 2013 11:15:52 +0000

Thirteen years passed before I returned to Denmark for a couple of days. In short: good friends, interesting history, and delicious food.

Sandhamn Off-Season

Fri, 05 Apr 2013 07:55:55 +0000

A weekday in April in Sandhamn: no people, no sound, almost no coffee. But plenty of water, plenty of sun, and still plenty of ice. Here are some impressions. And a riddle: what is 北京八?

Langstreckeneislauf aus der Sicht eines Deutschen

Fri, 05 Apr 2013 04:14:34 +0000

Wandern in den Bergen ist in Deutschland ein beliebter und allseits bekannter Freizeitsport. Wandern auf dem Eis mit Schlittschuhen hingegen ist hier größtenteils unbekannt. Eissorten abseits der Eisdiele? Abschnallbare Kufen? Isdubbar? Fahren auf Eisschollen? Mehrere dutzend Kilometer? Gefährlich? Eine Geschichte eines deutschen Anfängers über den ersten und intensiven Kontakt mit dem Langstreckeneislaufen in Schweden.

Ice around St. Saltkråkan

Wed, 27 Mar 2013 03:57:16 +0000

Newly frozen black ice in Stockholm’s Archipelago on March 16. Alone the tour I went with populated the ice with 250 people, which is four buses worth. The frozen sea was beautiful but sometimes treacherous – as ever, carefulness is your best buddy.

Ice near Vålarö

Mon, 11 Mar 2013 12:54:07 +0000

What is more to say after more than 200 kilometers on the ice? That it looks differently every month. And in March, I got the opportunity to see an amazing mixture of old thick ice, new thin ice, and sea water.

Ice on Vättern

Tue, 26 Feb 2013 16:55:29 +0000

After many days of adverse weather conditions, an ice-skating tour brings me to the second-largest lake in Sweden – which is three times larger than Bodensee (Lake Constance). Parts of the lake were covered with transparent ice with a hard and level surface.

Prolonging the Life of a Logitech K340 Keyboard

Mon, 25 Feb 2013 02:29:56 +0000

Successful life-hacker experiment: Removed all the keys from the keyboard, washed both keys and chassis, and almost as good as new. A Swiss knife is useful, but not absolutely necessary.

Computing PageRank for the Swedish Wikipedia

Mon, 18 Feb 2013 08:02:43 +0000

Time to play search engine and experiment with PageRank. How much time does it take to page-rank a network with a million pages? I got curious during working on a university exercise and tested two power iteration variants and one Monte-Carlo method.

Week Numbers in Google Calendar

Sun, 17 Feb 2013 08:25:47 +0000

The schedules of most courses at KTH are formulated in terms of week numbers. Google Calendar has a hidden feature for those, who are not yet used to remembering the current week number.

Ice in Mellanskärgården

Sun, 03 Feb 2013 12:55:46 +0000

Impressive experience on the ice in the middle parts of Stockholm’s archipelago — thanks to a phenomenal friend.

Ice on Stora Värtan

Sun, 03 Feb 2013 12:40:28 +0000

Gemütliche ice-skating tour on Stora Värtan. Small sight-seeing à la Shackleton included.

Case Study: Role-Playing Game in C++

Wed, 30 Jan 2013 09:48:54 +0000

A minimal implementation in C++ of a role-playing game with 2D graphics, as part of an exercise at university.

Winterness Around the Corner: Tyresta National Park

Sun, 27 Jan 2013 10:12:43 +0000

As an allusion to a previous article about the wilderness in Tyresta National Park, here is a short report on the winterness in the same place but during another season. Looks completely different.

Ice on Rönningesjön

Sun, 27 Jan 2013 09:17:01 +0000

It is just appropriate to praise the public transport from time to time. Especially if it makes a trip to a frozen lake a breeze. This time it was Rönningesjön near Täby. The snow was cleared from a circular track on the lake that used to be a bathing place in summer.

Artificial Neural Network: Animation of Training

Thu, 24 Jan 2013 17:04:49 +0000

See a live animation of how an artificial neural network is trained to represent a Gaussian-shaped function.

Inspecting Algorithms with Graphs

Tue, 22 Jan 2013 15:31:28 +0000

Graphs and algorithms are tightly connected. One surprisingly simple way to inspect algorithms graphically is to let the algorithms plot graphs during their execution using GML (Graph Modeling Language). The produced graphs can be formatted with graph editing software.

Missing in Sweden: Amazon

Tue, 22 Jan 2013 12:49:20 +0000

Strange but true: there is no Amazon in Sweden. I conceive this country as very eager to adapt new concepts and cutting-edge technology. Connectivity to the Web is ubiquituous. However, to my big surprise, there is no www.amazon.se. I could not find a matching Swedish counterpart either. Why?

Ice on the Baltic Sea

Sun, 20 Jan 2013 11:17:08 +0000

Magnificient ice on the Baltic Sea within Stockholm’s Archipelago, as discovered on a tour 20 kilometers east of Norrtälje.

HP Officejet 6500 e710n-z on Arch Linux

Fri, 11 Jan 2013 05:47:35 +0000

A road story on how to use my HP Officejet 6500 E710n-z printer on Arch Linux without dispensing the duplex unit and the feed scanner.

Ice on Norrviken, Edsviken, Brunnsviken

Wed, 09 Jan 2013 15:36:26 +0000

Getting the better part of the nordic winter: An ice-skating tour in the darkness from Norrviken to Brunnsviken, The evening was rounded off by some beer at Karlaplan. What else to expect from live?

Ice on Östermalms IP

Tue, 08 Jan 2013 13:14:41 +0000

How to create a nice area for ice-skating? “Deep-freeze” a stadium, clear huge amounts of snow, and turn on the floodlights. While ice-skating on a lake is definitely better, the circle at Östermalms IP is large enough to offer space for skaters at all kinds of speed and abilities.

Task Manager with Focus on Usability: dropandforget

Mon, 07 Jan 2013 01:28:07 +0000

Entering a TODO item into a task manager should be as easy as typing a few words and hitting enter. Moving your TODO item to another list should be exactly one mouse-click away. All lists should be shown at once. The experimental task manager “dropandforget” does just that.

Ice on Vallentunasjön

Sun, 06 Jan 2013 12:57:41 +0000

Many thanks to those who know the ice and made me have a wonderful day on the frozen Vallentunasjön – igen: tusen tack till dem som gjorde det möjligt.

Netgear WNR612 Classic Wireless Router – Good Value for Money

Sat, 05 Jan 2013 10:05:49 +0000

Surprisingly much for the price of 299 SEK: while the range is rather limited, the router features a separate guest network, an intuitive and comparably well-designed user interface for router management, okayish help information, humble packaging, factory defaults easy to find, a short Ethernet cable, and two years guarantee. Good for private use. Quality needs to be appreciated!

Version Control on Top of Dropbox

Fri, 14 Dec 2012 03:15:08 +0000

Suppose, two people are working together on a set of files. How to find a version control solution that is accessible for everyone (such as Dropbox) and powerful enough for sharing code (such as git)?

Vetenskap och konst - Julkonserten 2012

Fri, 14 Dec 2012 01:51:46 +0000

KTH’s Christmas concert 2012 offered a diverse composition: traditional Christmas pieces, a Lucia procession, and an extract from Bach’s Weihnachts-Oratorium (Christmas Oratorio).

Secondhand Course Literature in Stockholm

Mon, 10 Dec 2012 07:43:15 +0000

Being sick of expensive course literature in Stockholm? Relief is on the way: Secondhand books can be bought at Campusbutiken of Stockholms Universitet. There is also an online platform kthbok.com which performs a similar duty without taking detours via a reseller.

Swedish in Sweden - Musings about Motivation

Sat, 08 Dec 2012 15:09:40 +0000

Musings about motivation: the last part of a series in favor of learning Swedish while in Sweden.

Public Transport in Munich now on Google Maps

Thu, 22 Nov 2012 14:20:45 +0000

Finally! Now it is possible in Munich to look up directions and connections with public transport on Google Maps (bus connections are still missing!). According to Süddeutsche Zeitung, this took MVG (the local company responsible for operating public transport) a whole man year to finish the interface to Google Maps.

Quick-fix for X11: Typing Å on German Keyboard

Sat, 17 Nov 2012 11:36:51 +0000

German keyboards come with ÄÖÜ. But they lack the character Å, which is frequently used in Scandinavian languages. Here is a quick-and-dirty fix to customize the xkb map for X11 on Arch Linux.

Swedish in Sweden - Practice and Rehearsal

Wed, 14 Nov 2012 11:18:10 +0000

When learning a foreign language, there is an abundance of new words, new grammar, and new expressions coming in. Rehearsal is necessary in order to keep the learned items in memory. Much practice is required in order to turn passive understanding into readily available active language skills.

Swedish in Sweden - Learning to Listen

Wed, 14 Nov 2012 11:17:47 +0000

What use is it to ask someone in Swedish and then not to understand the answer? How to get the pronunciation right without being able to listen to Swedish? These two thoughts made listening a top priority for me when I started a new foreign language.

Swedish in Sweden - Gathering New Input

Sat, 20 Oct 2012 08:28:05 +0000

When learning a foreign language, full immersion probably guarantees a nearly unlimited supply of new words, new grammar, and new expressions, which never comes to a halt. When immersion is not possible, how to react?

Swedish in Sweden - Translation Tools

Mon, 15 Oct 2012 17:09:43 +0000

The best way to find a good Swedish translation while in Sweden is to ask a Swede. Of course. And there is no surprise here. However, there are a couple of resources available on the web that help with translation when professional help is not available.

Swedish in Sweden

Mon, 15 Oct 2012 17:05:30 +0000

Swedes talk Swedish. Surprised? Swedes always talk English with you as a foreigner? Well, the game can be changed and it is not too hard for native speakers in German or English. This is the start signal for a six-part article series about how to concretely speed up your progress in learning Swedish as a foreign language, based on my experiences. Why not just talk English? This crucial question is tackled first.

Rudimentary Recognition of Spoken Words at KTH

Fri, 12 Oct 2012 10:44:56 +0000

Pattern recognition (EN2202) at KTH Stockholm turned out to be a very good course, concerning lecture, exercises, and the accompanying project work. Together with a fellow student, we created a rudimentary recognizer for spoken words. It is far from production quality, of course. While a good part of the coding has been prepared for the students, the task left enough freedom to play around with hidden markov models in the context of word recognition.

Recognizing Textured Planar Objects with OpenCV

Tue, 09 Oct 2012 16:01:31 +0000

How can we recognize textured objects under the assumption of planarity in images? OpenCV provides extensive support for this task, and helps with local feature extraction, fast approximative matching, and robust model fitting. This article describes a minimalistic detector based solely on OpenCV for all vision subtasks, and also offers pictures, videos, and the source code.

Stockholm in Autumn - Worth a Thousand Words

Fri, 05 Oct 2012 14:26:57 +0000

Autumn has arrived and Stockholm dresses itself in wonderful colors. The magnificient scenery is definitely worth a few pictures.

TUM @ KTH Go Global Exchange Fair 2012

Wed, 03 Oct 2012 07:53:02 +0000

In 2012, KTH Stockholm offered an exchange fair for local students that want to go abroad. We organized a booth for Technische Universität München.

The Viterbi Algorithm and Breadth-First Search

Thu, 27 Sep 2012 15:20:21 +0000

Given a hidden Markov model, we can use the Viterbi algorithm in order to compute the most likely sequence of latent states that produced a certain sequence of observations. Neat: the algorithm is sort of breadth-first search for a maximum in a certain perfect N-ary search tree.

Vetenskap och konst - Fyrverkeriorkestern 2012

Wed, 12 Sep 2012 15:47:39 +0000

Charming. Unbeatable. Inconceivable. So much to the concert at KTH in Stockholm on September 12, which featured a variety of enjoyable pieces and culminated in the overwhelming “Music for the Royal Fireworks” (G. F. Händel). A fantastic display of music and fireworks in the Borggården of KTH main campus in a chilly late summer night.

Two Semesters at TUM - Four Periods at KTH

Mon, 03 Sep 2012 15:54:02 +0000

Technische Universität München (TUM) divides the academic year into a summer semester and a winter semester. However, it is four periods instead of two semesters at KTH Royal Institute of Technology. Here is a glance at some of the implications that I can see.

Biking in Stockholm - Practicalities and is it worth it?

Mon, 03 Sep 2012 14:28:48 +0000

Where to get a bike in Stockholm? Where to put the bike? And is it worth bicycling in Stockholm? While the practicalities are not easy to address, the efforts certainly pay out as a first trip indicates.

Arch Linux: switched to systemd

Sun, 02 Sep 2012 01:33:43 +0000

Time was ripe for me to migrate my Arch Linux installation from SysV to systemd. The transition was simple enough and turned out to be smooth in my case. There were not any troubles to be resolved. Furthermore, systemd made a very good first impression.

Överraskning: min kurs är på svenska

Tue, 28 Aug 2012 13:10:46 +0000

Why is the lecturer talking Swedish? Kursen är på svenska, förstås! I noted with some surprise that one of my courses is given in Swedish. It turned out to be a very welcome opportunity to listen to Swedish in a multi-modal setting.

Swedish Krona reaching 12-Year High against the Euro

Mon, 27 Aug 2012 11:31:43 +0000

Unfortunate for all those who have to exchange euro for Swedish krona: the krona has reached a 12-year high against the euro in August 2012. This is a rough 10% loss compared to last year.

Rotating Backups with rsnapshot

Sun, 26 Aug 2012 10:00:10 +0000

Looking for a light-weight, space-efficient backup solution for your data on local machines and remote servers? Give rsnapshot a try: relying on existing toolchains, opting for convention over configuration, and simple customization for slightly trickier backup tasks.

Shout it out loud every Tuesday: Living in Lappis

Thu, 23 Aug 2012 13:07:06 +0000

Every Tuesday one can hear random shouting at 10 pm in Lappis, a big housing estate near Stockholms universitet and KTH Stockholm.

KTH Campus Valhallavägen: Attack of the Clones

Tue, 21 Aug 2012 16:04:04 +0000

Fearsome clone troopers are patrolling the campus! What is happening on the campus of KTH Royal Institute of Technology in Valhallavägen?

Wilderness Around the Corner: Tyresta National Park

Fri, 17 Aug 2012 13:44:15 +0000

Tyresta National Park is merely an hour away from Stockholm, and is mostly rocks, wood, water. A special feature is a large area that was flame-cut by a raging wildfire in 1999, now offering a rough and strange landscape.

Splendid: Swimming in Stockholm

Mon, 13 Aug 2012 15:06:36 +0000

Stockholm is said to have very clean water. Indeed, I can only agree. Clean, refreshing, and open to everyone: swimming in Stockholm’s waters is excellent. What a welcome contrast to the lukewarm dirty waters around Hong Kong.

München-Stockholm by Train includes a Ferry-Ride

Wed, 08 Aug 2012 14:04:22 +0000

Travelling from Munich to Stockholm by train seems to be a crazy idea at the very first glance. However, coming at a price of 39,- EUR and virtually no baggage limit, I chose to take a 21h train ride on me to Stockholm via Nürnberg, Hamburg and Copenhagen with Deutsche Bahn. While the crowded trains made the journey tougher than expected, I was surprised by getting a ferry-ride for both the Intercity Express and myself.

Olve Maudal and Deep C++

Fri, 15 Jun 2012 13:46:23 +0000

Wonder about the depths of C++? Wonder why the code you wrote yesterday no longer works in the morning? Olve Maudal stated on TNG Big Techday 5 in Munich that you ought to look under the hood when you want to understand more about C++. His key statements were: C++ is fast and powerful. Yet, a shark is always lurking in your back, so have an appropriate model in mind. I enjoyed the talk, for more about this, see Olve Maudal’s blog and the freely available slides on the topic.

Mappotino: A Robot for Exploration, Mapping, and Object Recognition

Sun, 27 May 2012 09:56:30 +0000

How can we let a robot create a map of an unknown indoor environment using three cameras that simultaneously provide depth information and color images? We investigated this question in a four-week practical course at our university. This article sheds some light on the challenges involved.

Matchmaking on a Shanghainese Sunday

Sun, 25 Mar 2012 08:58:42 +0000

The public parks in Shanghai attract lots of people, especially on Sundays. As described in a previous article, these parks offer plenty of opportunities for a variety of leisure activities. Actually, the People’s Park on People’s Square features the most curious of all the Sunday activities I have seen so far.

Boxing Boats on a Shanghainese Sunday

Sun, 25 Mar 2012 08:58:01 +0000

The city proper of Shanghai is home to 20 million inhabitants (see here and here). Unsurprisingly, despite of its density, the urban area goes on and on. Nevertheless, if people want to enjoy nearby green areas in their spare time, they have at least the public parks.

Chinese Trains: the Fast and the Curious

Sun, 25 Mar 2012 08:53:56 +0000

Taking the train is a common way of travelling in China and popular amongst locals and foreigners. Westerners might find some surprising facts about travelling in China by train.

Sheepish: No Mercy for Pedestrians in China

Sun, 25 Mar 2012 08:51:53 +0000

Traffic in China follows other rules than in Germany. Also the assortment of vehicles in China is much more diverse; featuring trucks, buses, taxis, private cars, electric scooters, motorcycles, bicycles, three-wheeled cars and pedestrians all sharing the same space.

Template Tracking using Hyperplane Approximation

Sat, 11 Feb 2012 05:19:25 +0000

Tracking an object over a sequence of 2D images is a challenging task. One approach uses a linear mapping between observed intensity differences and target motion; this is presented in the paper Hyperplane Approximation for Template Matching by F, Jurie and M. Dhome. Here are some results from an implementation in Matlab by a fellow student and me.

Fix for Wireless Presenters and Flash-based Full-screen Prezi

Thu, 12 Jan 2012 09:53:14 +0000

Your wireless presenter is not working for prezi.com in full-screen mode? Here is how you might be able to fix the issue on X-based Linux desktops by temporarily remapping the “Page Up” and “Page Down” buttons of your keyboard.

Reinventing the Wheel: Panorama Stitching with Matlab

Tue, 06 Dec 2011 13:06:59 +0000

A set of images that have some common overlapping regions can be stichted together to form a panorama picture. Some recent camera models can even compute the panorama picture internally and do not require post-processing on the computer. While this is a problem that has already been solved (for example, there is AutoStitch, here are some hints on classic DIY-panorama-stitching using Matlab, SIFT, DLT and RANSAC.

Saving the Parrots with Homogeneous Coordinates

Wed, 09 Nov 2011 08:25:24 +0000

A well-known result from linear algebra is that one can use a matrix to represent any linear mapping between two vector spaces. While rotation is a linear mapping, translation unfortunately is not. But, wait… by adding another dimension to the vector space, and by interpreting the vector coordinates correctly, we are able to perform rotation and translation with a single matrix multiplication! This article describes how to restore a fragmented image with the help of homogeneous coordinates.

A Connection between Motion Blur and the Fourier Transform

Sat, 22 Oct 2011 04:20:07 +0000

Motion blur usually occurs in an image, when the camera was moved with respect to the subject. Motion blur has an interesting effect on the Fourier-transformed image, as pointed out by D. Burschka at University of Technology, Munich. Here is an example how the Fourier-transformed images of toy images look like that have been subject to motion blur.

Disabling hot-corner effect in Gnome 3

Fri, 21 Oct 2011 13:05:56 +0000

When using Gnome 3, one can access the dashboard by moving the cursor to the top-left corner of the screen. As it turns out, I always kept accidentally moving the cursor to this “hot corner”, thereby opening the dashboard involuntarily. Here is a small hack that disables this hot-corner effect. You are still able to show the dashboard by activating the “super” key.

Dual-booting Arch and Ubuntu with LVM on top of LUKS

Sat, 08 Oct 2011 15:18:14 +0000

Encrypting your hard drive is generally a good idea. Yet, the encryption renders dual-booting a little more difficult. Here I briefly sketch how I installed Ubuntu in parallel to an existing Arch installation on a LUKS-encrypted drive.

Team Black Sheep presents amazing stunts with first-person-view RC plane

Fri, 27 May 2011 13:17:28 +0000

Being suprised by a low-flying unidentified objects? Maybe it was just a remote-controlled airplane by Team Black Sheep, who were giving a talk at TNG Big Techday in Munich on 2011-05-27.

Sampling from a Poisson distribution - a benchmark

Fri, 13 May 2011 22:52:24 +0000

Having a poisson-distributed random variable X, how can we efficiently generate samples (or say realizations) of that random variable? This article shows how Knuth’s technique can be derived and it also indicates that the Ratio-of-Uniforms method is quite efficient.

Understanding someone else's source code

Wed, 09 Mar 2011 13:50:17 +0000

Who has the luxury of working on a green field project where you can write everything from scratch, and thus feel in control about your code? I usually don’t. There are several good reasons that force programmers to develop their skills in reading code they have not written by themselves. You might want to add a feature (extending existing code), fix a bug (maintaining existing code), look for inspiration (learning from existing code) or integrate functions into another project (reusing existing code). All of these goals require you to read code.

Enhancing Details with Unsharp Masking

Mon, 25 Oct 2010 09:05:58 +0000

Unsharp masking is an image enhancement technique that sharpens an image and highlights fine detail and put more weight on edges. By subtracting a blurred version of the original image, one obtains an unsharp mask that in turn can be added to the original image. An easy-to-digest explanation can be found in the “GIMP help pages”:file:///usr/share/gimp/2.0/help/en/plug-in-unsharp-mask.html. Here is an example of a picture before and after unsharp masking:

Nearest-Neighbor-Resampling in Matlab

Thu, 14 Oct 2010 19:07:10 +0000

This article shows the derivation of an algorithm for resizing images in Matlab, using nearest-neighbor interpolation. Scaling an image is mathematically just multiplying image coordinates by a scaling factor. Surprisingly, when dealing with digital images, the scaling process becomes a little bit more complex.

Zweidimensionale Bereiche plotten mit Wolfram|Alpha

Thu, 24 Jun 2010 15:05:23 +0000

Besonders nett und nicht nur zum Entwerfen von Tapetenmustern hilfreich. Wolfram|Alpha zeichnet Bereiche im R^2. Beispiel:

Hosting bei Dreamhost, Domain woanders

Wed, 16 Jun 2010 08:30:34 +0000

Über wenige Webhosts lassen sich beliebige Top-Level-Domains registrieren. Beispielsweise ist es derzeit (Juni 2010) bei Dreamhost nicht möglich, de-Domains zu bestellen. Bei deutschen Anbietern wiederum ist dies möglich, im Niedrigpreissektor z.B. bei Evanzo. Bei Evanzo hat man Zugriff auf die DNS-Einträge der Domäne.

Eine weitere Identität für Binomialkoeffizienten

Thu, 20 May 2010 02:29:51 +0000

Keine besonders umwerfende Erkenntnis, aber diese Identität hat mir letztens weitergeholfen:

$${n \choose a} {n-a \choose b} = {n \choose b} {n-b \choose a}$$

Remote Procedure Calls über den DBus

Tue, 27 Apr 2010 12:12:52 +0000

Wozu dient der DBus? Und wie spricht man ihn an? Ein einfaches Beispiel in fünf verschiedenen Sprachen — mit Java, OCaml, Python, C und der Shell!

2D-Grafik-Ausgabe mit Cairo und OCaml

Sun, 11 Apr 2010 12:31:09 +0000

Feldversuch. Wie funktioniert Cairo in Verbindung mit OCaml?

Programmierkonzepte für Multi-Core-Prozessoren

Fri, 02 Oct 2009 10:30:54 +0000

This article briefly introduces some existing programming concepts. It is a summary of a couple of interesting approaches that were presented at Ferienakademie 2009.

Funktionsgraphen zeichnen mit PostScript

Wed, 16 Sep 2009 14:40:48 +0000

PostScript ist eine Programmiersprache, die zur Beschreibung von Seiten dient. Mit ihr programmiert man direkt auf dem Stack und nutzt dabei die umgekehrte polnische Notation, was einigen Spaß bereitet, sobald man mal den Dreh herausgefunden hat. Mit PostScript kann man programmatisch skalierbare Grafiken zeichnen.