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posts for 2014.

this christmas, we visited ivalo in finnish lapland. we had plenty of snow, it was freezing cold (between -13 and -30 degrees celsius), and the sky was often clear – perfect conditions for auroras!

during daytime, short as it was, we did an excursion to the siida museum in inari, to saariselkä, and via utsjoki to norway.

finally, here are some aurora animations:

after already revamping math and musikwiese earlier this month, it’s time to do spielwiese as well. and here we go! spielwiese now adjusts to all window widths, including mobile phones. and the gallery looks good again, too. (i had to screw with it when adjusting spielwiese for mobile phones the first time.)

the only things missing are a proper popup gallery for mobile phones, and as in the other blogs: comments. so sorry, there’s no way to add a comment at the moment, except by writing me an email.

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over the last weeks, i’ve been starting to convert my blogs to nikola, a static blog generator named after nikola tesla. so far, i’ve finished my math blog and musikwiese. i also got rid of the fixed width layout. spielwiese itself will take a bit more work, mostly because of the wordpress plugins i wrote and heavily rely on throughout this blog.

to convert my blogs, i had to add some changes to nikola. most of the core changes are now contained in nikola itself or are close to be integrated (except xhtml support). i also worked a lot on improving its wordpess import, which so far wasn’t very helpful from my point of view. for that, i created a wordpress page compiler for nikola which essentially does the same to posts as wordpress’ formatter does. that part is still not completely done, and since it is a pure plugin, i haven’t released it yet. (that will happen later, hopefully still this year.)

the main disadvantage of the whole conversion process is currently that there’s no more possibility to add comments. all comments written so far are preserved, but currently there’s no support for adding new ones. i’ll try to figure out a good way to do that later. the “standard way” to do that, i.e. using something like disqus, is not acceptable for me, and even though there are free alternatives for self-hosting, i don’t like to rely on javascript for such things. for the moment, you have to send me an email if you want to add a comment to musikwiese or my math blog.

two days ago, alexander grothendieck, one of the greatest mathematicians of the 20th century, died. i’ve seen a small excerpt of his work in algebraic geometry and commutative algebra during my studies, phd and postdoc times. without his work and ideas, the theory of schemes wouldn’t be what it is today, and without it, the study of elliptic curves over rings might have taken quite a different road. (elliptic curves over rings are a topic i’ve been very interested in while working on my diplom thesis.) even though his active mathematical career stopped over 40 years ago, his work had an immense influence on generations of mathematicians.

rest in peace.

(a great obituary can be read at the telegraph.)

last weekend we visited freiburg in germany, to attend a concert by reinhard mey. the concert took part in a huge exhibition hall. seating around 4140 persons according to the hall’s homepage, it was one of the hugest concerts i’ve been at (excluding concerts in stadiums where everyone was standing). since reinhard mey plays all by himself – only he, his guitar and his voice –, there wasn’t that much to see from where we were seated (and that was still far from the back of the hall). but then, the music counts. and the music was great!

on the next day, we explored freiburg. freiburg is quite beautiful and mostly pedestrian friendly, even though it’s currently crowded with construction sites. (most important consequence is that the trams cannot go to the old city center anymore.) later, we travelled to the schauinslandbahn, a gondola tramway going up a mountain called schauinsland by over 700 meters to a total elevation of 1284 meters. we had a quite beautiful view from there! too bad i didn’t bring any good camera with me… (the fairphone‘s camera isn’t precisely good… even a bit worse than an iphone4 camera. but well, i didn’t buy it for its camera :) )

on the east side of canada, we began our journey in toronto. from there, we directly continued to the town of niagara falls, ontario.

niagara falls.

in niagara falls, we saw the niagara falls. they are quite impressive. less impressive, though, is what was build around the falls. the town is essentially a big amusement park with two casinos (a third on the american side). no place i’d like to stay long at.

kingsville, windsor and detroit.

from niagara falls, we continued to kingsville. from there, we saw lake erie, and went on a trip to windsor, from where we could glance over to detroit.


finally, we ended up in toronto. my third visit. we spent one day exploring toronto by bus (hop-on hop-off) and boat (around toronto islands). it was somewhat cloudy, with a lot of wind, so the view of cn tower changed between a large stick ending up in the clouds and seeing the full tower up to its tip. eventually, we went up the tower (we had a great dinner there). it was still cloudy, and most of the time we couldn’t see anything of the city. but the view was great, nonetheless: we experienced a wonderful sea of fog! (almost like in the swiss alps. yay!)

toronto zoo.

on one day in toronto, we chose to visit its zoo. the zoo itself is quite nice, and they currently have panda bears as visitors!

what’s not so great is actually getting to the zoo. from downtown toronto, you have to take the subway (if you’re not at the main west-east line, you have to change subway lines) and then continue by bus. we went to union station and tried to use a ticket vending machine, but it didn’t offer the zoo as a destination. so we lined up, and were finally told that we need two tickets: one for the train and another for the bus. turns out, union station is used both by subway and train, and obviously, we tried to use the wrong vending machine and lined up at the wrong counter. and obviously, why should two different transportation companies cooperate and make travelling accross the borders of the two systems easy to use (especially for tourists)? this isn’t switzerland (or germany), after all. yay. eventually, we arrived at the zoo (with still two changes, but fifteen minutes earler than we should have been there with subway and bus).

well, that was everything. in three weeks, we saw quite a lot of canada, and there’s still that extremely much more to see! for the next time we will be in canada (eventually; will still take some time :) ) we plan to explore the east somewhat more, in particular the parts not so densely populated as the area around toronto, like newfoundland and labrador and nova scotia. and of course also quebec, and also canada’s capital, ottawa.

during the second half of september and the first few days of october, we were roaming through canada. we spent two weeks in the west and one in the east. revisiting some places i’ve been earlier, and visiting a lot of places i’ve never seen before.


we started in vancouver.

next, we set over to vancouver island and crossed the island to its west coast.

little quasicum falls.

on our way to the west coast, we stopped at the little qualicum falls. (our first waterfall on this trip, but definitely not the last.)

on the west coast, we stayed in ucluelet.


ucluelet is a nice place placed directly at the pacific ocean. the following pictures are from a nice walk near the lighthouse.

long beach near tofino.

from ucluelet we continued northwards in the direction of tofino and stopped at long beach. after somewhat cloudy weather in ucluelet, the clouds opened up here and we had nice sunny weather. obviously, we put our feet into the ocean.

later, we continued to victoria. the last two of the above photos were taken near port alberni.

heading northways.

from victoria, we set back to the mainland and continued north. we took a tram up a mountain near squamish, had a little stop-over in whistler, and then continued north-east until we arrived in clinton.

continuing north.

from clinton, we headed north to prince george.


barkerville is an old gold-mining town not too far from prince george. on our trip to the latter, we did an excursion to barkersville.

crossing the rocky mountains in the north.

from prince george, we continued north-east to dawson creek, from where we continued to Grande Prairie and then headed south to jasper.

the northern part of the icefields parkway.

from jasper we travelled along the icefields parkway. or at least its northern part. it was a very nice trip, with one exception: the so-called glacier skywalk. despite its name, it has not much to do with glaciers. the landscape you can see was formed by glaciers, and you can see glaciers from far away – but that’s it. you can get way better views of still-alive glaciers (like the columbia icefield) for free and not far from there.

don’t get me wrong, the construction of the skywalk is great (from a technical point of view), but the name’s a terrible choice and quite disappointing. (an interesting fact is that roughly at the place where the skywalk is built, i remember a stop at the street where you could stop your car and take a look. the view was similar to the one from the skywalk. now you can’t stop there anymore, but have to pay quite some bucks to be transported there by bus.)

heading east.

from roughly the middle of the icefields parkway, at saskatchewan river crossing, we headed east along highway 11. the mountainous landscape changed to endless farmland, endless straight roads with regular (every 25 kilometers or so) perpendicular intersecting roads. except from slight elevation changes, you it feels like you can drive forward forever. eventually, we headed south, though.

drumheller and the alberta badlands.

our next destination was drumheller in the heart of the alberta badlands. from there, we explored the badlands a bit, in particular we saw horsethief canyon, horseshoe canyon, and the famous hoodoos. unfortunately, we had several rainshowers inbetween…


from drumheller we continued to vulcan, where we visited the tourist information as well as the trekcetera museum. thanks a lot to devan and michael for showing us around both places! (besides, a museum where you are even encouraged to take photos is a great museum!)


finally, we ended up in calgary, where i used to live for quite some time. this was the first time i visited calgary as a tourist, and it turns out there are quite some things to see you wouldn’t expect. if you ever want to explore calgary, you should visit the calgary tower – they have a great electronic tour guide, which is essentially a smartphone where you can click on buildings you can see and get audio information, sometimes also videos, about the places. it also included some material on last year’s flood, so it looks like it’s pretty new. i hope they’ll keep it and also keep it up to date.

the other great thing we did was a city tour on calgary’s only hop-on hop-off bus. apparently not well known, we happened to be the only two passengers for our tour. which was great for us, since our guide was really fantastic (he used to guide tours in the rocky mountains before)! he explained and showed us lots of things we would have never seen or heard about. he also showed us some nice places which are usually not part of the tour. it’s really a shame that this tour is not more well-known.

from calgary, we took a plane to toronto.

recently, in a bookstore, i stumbled about a book called the martian, which tells a story about an astronaut who gets stranded on mars and tries to survive. i really enjoyed reading it, after all the story sounds quite realistically to me. it’s a great book indeed! if you like hard scifi, it’s definitely worth reading.

one thing which was nagging on me while reading the book was that the author’s name, andy weir, sounded somewhat familiar. even though this was supposed to be his first book. well, while reading on, my suspicion grew that andy was somewhat releated to a webcomic i used to read, called casey and andy. (it’s basically about mad scientists. lots of nerdy humor!) and indeed, after finishing the book, i tried to look this up, and found out that casey and andy was written by someone called andy weir, and his homepage also features a section creative writings, where he also mentions his book the martian. bingo!

it’s really cool to see that someone who created a webcomic (one i really enjoyed!) to be (somewhat) commercially successful – after all, there are plans to make a movie out of the martian, directed by ridley scott and featuring matt damon.

yesterday, we visited the pizol. getting up was quite an adventure, though; we first travelled via train to bad ragaz, from where claimed bus 456 (a postauto) proceeds to the cable car station. unfortunately, as it turned out, the bus is only going during winter season. as we were waiting where it should leave, we noticed another small bus with “pizol” largely printed on it leaving at the designated time. the bus was hidden behind another postauto when we got out of the train station, so we only noticed it when it was leaving. since we weren’t the only ones standing at the postauto stop waiting for bus 456, we were a bit confused, and finally went to ask in the train station. turns out, they knew that the bus was still written on incorrectly and already passed the message on several times, but nothing happened. so we waited one hour for the next bus (walking would have taken around 40 minutes, but that’s not too much fun at over 30 degrees in the sun). well, when the (private) pizol bus finally came back, we also tried to inform the driver, who apparently never before heard about this problem. he also mentioned that from next year on, there will be a postauto also during summer… well, we hope that maybe now someone will put up a sign at the postauto stop that the bus is currently departing from somewhere else…

anyway, we finally took up the cable cars to laufböden, from where we wanted to walk the panorama trail (should be around 60 minutes). interestingly, the only sign up there pointing to the destination of the panorama trail said it would take 20 minutes. with no real different choice, we started walking that direction, until after 50 meters or so we found another sign, splitting up between the direct route (“standart-weg”) and the panorama trail. we continued the panoramic trail, though in the end we noticed we apparently screwed something up, as when we arrived at a lake inbetween, we saw that the panoramic trail leaving from there to our starting point left in another direction… whatever… anyway, we had a nice view, and up there the temperature was really nice and bearable. we also were able to put our feet into the lake, which was very refreshing. after circling the lake, we continued the trail to the pizolhütte where we had lunch, and finally proceeded down.

overall it was a very nice excursion, except that getting there (and also getting back to the train station) via public transport is apparently somewhat more complicated…

i’m very happy to announce that the lattice reduction library plll has finally been released as open source under the MIT license by the university of zurich. during my recent years at the university of zurich, i’ve been mainly working on this c++ library. it supports a wide range of lattice reduction algorithms and svp solvers, and makes heavy use of c++ templates and has support for c++11‘s move operations.

in 2011, i began implementing it since i wasn’t happy with some of the behavior of ntl‘s lattice reduction algorithms (mainly: in case of fatal numerical instability, they just terminate the program, and the library cannot be used in more than one thread at the same time). back then, ntl’s main competior fplll didn’t support bkz reduction, so i decided to try things out myself. after some time (years), my initial experiments grew into a full library supporting not only the more common lll and bkz algorithms as well as svp solving by enumeration, but also several different algorithms for lattice reduction and svp solving which are described in literature but for which it is sometimes quite hard to find a working implementation of. though the implementations of these algorithms are still more on the experimental side, the basic algorithms such as lll, bkz, potentially combined with deep insertions, and enumeration, are well-tested over the years. (in fact, some large-scale lattice reduction experiments i did for these algorithms yielded some results in the svp challenge’s hall of fame).

in case you’re interested in this library, feel free to play around with it! in case you have any questions, encounter problems, or want to give feedback, feel free to contact me by email.