Previous Up Next

Diary, July 2022

Sun Mon Tue Wed Thu Fri Sat
                      1   2
  3   4   5   6   7   8   9
 10  11  12  13  14  15  16
 17  18  19  20  21  22  23
 24  25  26  27  28  29  30

Friday, July 1, 2022

AKI Finals

I went to the AKI finals 2021/2022 exhibitions at the AKI building. I found the works of the following graduated students noteworthy (in the order I encountered them):

At 19:49, I bought the finals catalogue ★MMXXII edited by Mirjam Leppers and Ina Bode, written in Dutch and English, and published by AKI Academy of Art & Design, ISBN:9789075522426, for € 15.00.

Saturday, July 2, 2022


In the past weeks, I worked on the firmware for the MCH2022 badge in particular the menu for connecting to the hatchery and downloading apps to the internal storage of the badge. The file hatchery_client.c contains the code for querying the hatchery RESP API and processing the JSON responses. The most tricky part of the code, is the part that processes the Unicode espace sequences including the support for surrogate pairs.

Sunday, July 3, 2022

Woerden and The Hague

Conny and I went to The Hague. On the way there, we went to Woerden, where I lived from 1965 till august 1981. We walked aroung my old neighbourhood. Also along the primary school, I attended. Next, we parked in the city center, were we walked around and paid a short visited to the Bonaventura church, where only the enterance was open to the public. I spend many Sunday morning in this church. Along the gracht, we found a small, two floors house that was on sale. (Later in the evening, we found it was on sale for 425,000 €. Inside it looked quite nice and in the back garden there was a street tile pattern.)

After we had checked in with our hotel, we went to the most North part of the beach in Scheveningen. I walked into the sea some distance. (Picture.) The water was not really cold, about 16.5° Celsius according to some website. I got some spash of water in my hair when a wave hit me from the back when I walked back to the beach. We went over to beach bar Naturel were we had some drinks and dinner with a piece of cake as desert. Conny had a Kapsalon and I had a Tlacoyo Maduro. We hoped to see a nice sunset as the sky was clear, but at the horizon there were some clouds. We left the bar around ten and took some pictures of the sea while walking back to the parking place.

Street tile pattern

I spend some time reconstructing the street tile pattern in the back garden of the house. If I a not mistaken, the part that is visible in the pictures, looks like this:

This text is displayed if your browser does not support HTML5 Canvas.

At first, I thought that it was not very regular, but when I entered the data to create the above representation, I recognized many repeating patterns.

Monday, July 4, 2022

KABK Finals

I went to Graduation show 2022 exhibition at Royal Academy of Art. I found the works of the following graduates noteworthy:

Tuesday, July 5, 2022

Four bookshops

In the morning, I visited four bookshops: De Vries Van Stockum, Paagman, Mayflower Bookshop, and The American Book Center. At 10:11:58, I bought the book When the mood strikes...: Verzameling Wilfried & Yannicke Cooreman written by Ward Daenen, Tanguy Eeckhout, Museum Dhondt-Dhaenens (Deurle), and Lars Kwakkenbos, written in Dutch and published by Museum Dhondt-Dhaenens in 2009, ISBN:9789076034003, from bookshop Paagman for € 5.00.

Kunstmuseum Den Haag

This afternoon, Conny and I visited Kunstmuseum Den Haag together with Peter Struycken. First we went to see the Alphonse Mucha exhibition. There we saw the following works by Alphonse Mucha (if not attributed otherwise) among the works on display:

Then walked through (parts of) the exhibition Discover the Modern. We saw, among others, the following works:

After a short break, we went to see the exhibition Mondrian Moves with works by Piet Mondrian and others. We saw, among others, the following works:

Then in some other part of the museum, we saw (amongh other works):

North-East Chinese Eatery 东北小吃

For a dinner we went to North-East Chinese Eatery 东北小吃. We ordered the following dishes: The dishes were a bit larger than expected. We shared them among us as the Chinese are known to do. The dishes were also not all delivered at the same time, so it felt very Chinese. All dishes tasted as expected. Very nice experience.

We walked with Peter to Den Haag HS railway station. Along the way we came across the house of Baruch Spinoza, the house where he used to live for some years, and The Grey Space. On the way back to the hotel, we also show the electronic parst shop Radio Twenthe.

Too 'smart'

In the evening, I discovered that my implementation for the hatchery client of the MCH2022 badge was replaced by a new implementation using one of the standard JSON parsing libraries that construct a generic structure. I do not know why it was replaced but I guess that in a sense my implementation was too 'smart'. That is a problem with software development that sometimes you write code that is very specific and optimal for a certain application, but for that reason too inaccessible or complex for someone else who has to modify something about it and has not the time to delve into it and to understand the code. Maybe I too have fallen a bit in the trap of premature optimization and that a solution doing a lot of needles memory allocations and being less efficient was good enough in this case. Writing software is also about communication and similar to writing texts it can happen that you have misjudged your audience. This danger might even be bigger, because there are so many different programming styles.

Wednesday, July 6, 2022

Gerrit Rietveld Academie Finals

While traveling home, Conny and I went Amsterdam to see the finals exhibition at the Gerrit Rietvel Academie, I found the following things noteworthy (in the order, I encountered them):

Saturday, July 9, 2022

Summer sale

This afternoon, I went into the city. I first visisted Galerie Objektief, where I saw the exhibition Wasting time with photographs by AKI students. After this, I walked a bit through the city and went to bookshop Broekhuis where I looked at the new arrivals. Only when I went outside, I noticed that there was a summer sale. I went inside again and spend some time looking at the summer sale books. At 16:02:45, I bought the book I Am Spock written by Leonard Nimoy in English and published by Hachette Books in 2015, ISBN:9780316388375, for € 10.75 from the sale with a 50% discount.

Street tile pattern

Below there is a way in which the the street tile pattern could be completed to fill the garden (if I am not mistaken about the dimensions). It seems that it just the versaille tile pattern. It looks like this pattern can be used to fill any triangle.

This text is displayed if your browser does not support HTML5 Canvas.

Monday, July 11, 2022

Irregular grids

It has been some time since, I looked at the problem of the generations of irregular grids of squares and equilateral triangles due to being occupied with things among some preparations for MCH2022. I already started implementing a uniqueness test for the generated patterns by converting them to a graph and compare these graphs to see if two patterns are the same except for some translation and/or rotation. In the past days, I finished an implementation in a new version of irst.cpp. I does find some patterns to be the same, but I have not verify yet if it finds all the matching patterns. I think that for verifying this, I have to implement something to visualize the patterns and see if there are still patterns that are the same but not recognized as such.

Thursday, July 14, 2022

Quechua MH100 2P Fresh & Black

At the end of the afternoon, a Quechua MH100 2 person Fresh & Black tent and an air mattress from Decathlon arrived, which I had ordered on June 23. I bought them for when I go to MCH2022 next week.

Sunday, July 17, 2022

Aldo van Eyck

I finished reading the book Aldo Van Eyck, Humanist Rebel: Inbetweening in a Post-war World written by Liane Lefaivre and Alexander Tzonis, which I started reading on June 16 after I bought it on April 14. The book is about the Dutch architect Aldo van Eyck. It feels like the book is more targeted to people who know a bit more about architecture than a lay person like me. Too me the text felt a little suggestive at some places, trying to make connections with ideas from others for which I wonder whether Van Eyck has made these at well.

Tuesday, July 19, 2022

37.7° Celsius

The temperature at Twenthe Airport has gone up to 37.7° Celsius, which breaks the previous record of 35.6° on this date in 2006.

Wind direction graphs

The Royal Netherlands Meteorological Institute has some website showing the result of simulations runs to predict the weather for the coming two weeks. These also include fifth runs with slightly random disturbances to see how trustworthy the predictions are. To see these, one has to select 'Expertpluim' on the Weer- en klimaatpluim en Expertpluim page and click on the 'Toon' buttion. I am a little annoyed about graph showing the prediction for the wind direction (called 'Windrichting (graden)' because when the wind direction goes from, for ezample 10° to 350°, a change of 20°, it shows as a change of 340°. I find this very ugly.

Friday, July 22, 2022

MCH2022: Day one

This morning, I arrived at MCH2022, a hacker camp held in Zeewolde, the Netherlands. I spend some time setting up my tent and met some people. I also tested the badge and inserted the 32Gbite SD card I bought on Wednesday. From 14:00 till about 16:15, I did my first volunteer (angle) shoft as a running angle. Mostly spend my time at the delivery gate and one time escorted a camper on bike to the Fuze field, one of the camper fields. I got a food vouvher and a purple angle t-shirt.

At 17:00, I attended the opening at Abacus. At 18:00, I attended The Silicon Passion also at Abacus. I left before the end of the show. I went back to mmy tent, talked a bit there, and then walked around the campground. At 19:54, I arrived at Heaven, where dinner was served for the angles. It was a simple but teastfull meal that I shared with another man who I met in the queue. At 20:40, I attended the talk Hacking the genome: how does it work, and should we? by Bert Hubert. Afterwards, I went to the Unlock the City village, where I just saw the end of the Wardriver UK talk. This is about tracking the location of open WiFi access points. I walked around the bar area where there people playing with flam throwers and watched the music stage a bit and decided to go to the Silent Lounge where I completed writing this.

Saturday, July 23, 2022

MCH2022: Day two

Although I am staying in the quiet camping area at MCH2022, the noises from some of the stages at MCH2022 could still clearly be heard. I woke-up at 5:48 discovering that the battery of my mobile was extremely low. I decided to get up and go to the Silent Lounge to rechard my appliances.

At 11:00, I attended the Reverse engineering for beginners workshop. The first piece of reverse engineering was using procyon Java decompiler to reverse engineer a jar file. There was something to figure out and I wrote a piece of JavaScript, to produce: . Next we looked at some machine code and installed radare2. I did not get to use it because I decided that I wanted to visit some other talk.

At 12:30, I went to the self organized session Solid, Linked Data and Decentralized Web Meetup, where I attended the talks Funding 101: NLnet and NGI and Solid: Vlaanderen, Nederland, Europe. It was getting hot. I decided to have a warm lunch at Heaven.

At 15:17, I walked into the talk What have you done against covid (a personal retrospective).

At 16:12, I arrived at the Badge Workshop. It was quite busy, so, I sat on the ground and left about a quarter of an hour. I went to my tent and stayed there some time. I noticed that I have some problem with the heat, which makes it hard to think clear. As tomorrow it is even getting hotter and I feel kind of lost, realizing again that these kind of hacker camps are not really my kind of thing, I decided to leave tomorrow after I gave my workshop. I already brought some of my belongings back to my car.

At 22:00, I attended the talk Cryptography is easy, but no magic. Use it. Wisely. The talk was interrupted several times due to problems with the audio system.

At 22:48, I joined the (already ungoing) talk Non-Euclidean Doom: what happens to a game when pi is not 3.14159….

Sunday, July 24, 2022

MCH2022: Day three

Today will be my last day at MCH2022 camp ground. (I might follow part of the program at home.) In the morning, I emptied my tent and brought the remaining belongings to my car. The tent was still a bit wet (due to condensation) to be packed.

At 10:00, I attended the talk Running a mainframe on your laptop for fun and profit by Jeroen Baten.

At 11:00, I attended the talk Heuristic Park (why we can fake it until we make it). This talk made me think about the possible causes of the fake news. I felt that the speaker did not address all the why questions but primarily talked about the mechanism that are at work. I wonder if these mechanism can be countered if you do not address the why questions. But then I also realized that the answers to the why questions are hard to grasp for people especially when they are already trapped in fake news which in a way are similar to religious believe systems.

At 13:00, I gave my workshop A practical approach to parsing using . There were about 20 to 25 people attending the workshop of which most stayed till the end. Just the right amount. I was happy that so many people showed up also because it was already getting hot. When we came to the exersize part, people really got into it. Some people thanked me afterwards. I hope that some of them are able to put it to practical use or that it at least has been of some help thinking about issues related to parsing, abstract syntax tree, and interpreting. With one of the attendees I talked about the problem of writing a interpreter in JavaScript that can be interrupted when getting into an infinite loop. While driving home, I thought about the possibility of using an array to store the stack for solving the problem with recursive functions and being able to continue the execution after some user interaction. This would also allow you to implement a debugger.

Monday, July 25, 2022

MCH2022: Day four

After a good night of sleep, I watched and/or listened to parts of the following talks MCH2022 online:

Wind direction graph

I figured out how to make a nice wind direction graph using Highcharts. I did this, by replacing the getGraphPath method by a function that deals with the wrapping around of values. (I do not know how to this if you have multiple graphs on one web page where you do not want this on all graphs.) Below the effect of this is shown with some example data.

Tuesday, July 26, 2022

MCH2022: Day five

After a good night of sleep, I watched and/or listened to parts of the following talks MCH2022 online:

Wind direction graph

I have been looking into a way for when you are using Highcharts and are having multiple graphs on one webpage but you only want to modify the behaviour for a single graph. The solution I have arrived at for having an alternative implementation for getGraphPath is to look at some unique property of the chart, like the title or the container name, using the this.chart object. I managed to implement the nice wind direction graph in a local copy of the Weer- en klimaatpluim en Expertpluim webpage of The Royal Netherlands Meteorological Institute by inserting the following JavaScript code on line 341 in the HTML of the webpage:
var orginalGetGraphPath = Highcharts.seriesTypes.line.prototype.getGraphPath;
Highcharts.seriesTypes.line.prototype.getGraphPath = function(points, nullsAsZeroes, connectCliffs) {
  if (!this.chart.title.textStr.includes("richting")) {
    return, points, nullsAsZeroes, connectCliffs);
  var points = this.points
  if (points == undefined) return []
  var graphPath = []
  var height = this.yAxis.height
  var heightd2 = height / 2
  var prevPoint = points[0]
  graphPath.push(['M', prevPoint.plotX, prevPoint.plotY])
  for (var i = 1; i < points.length; i++) {
    var curPoint = points[i]
    if (prevPoint.plotY - curPoint.plotY > heightd2) {
      var f = (prevPoint.plotY - height) / (prevPoint.plotY - (curPoint.plotY + height))
      var midX = (1-f) * prevPoint.plotX + f * curPoint.plotX
      graphPath.push(['L', midX, height ])
      graphPath.push(['M', midX, 0 ])
    else if (curPoint.plotY - prevPoint.plotY > heightd2) {
      var f = (curPoint.plotY - height) / (curPoint.plotY - (prevPoint.plotY + height))
      var midX = (1-f) * curPoint.plotX + f * prevPoint.plotX
      graphPath.push(['L', midX, 0 ])
      graphPath.push(['M', midX, height ])
    graphPath.push(['L', curPoint.plotX, curPoint.plotY])
    prevPoint = curPoint
  this.graphPath = graphPath
  return graphPath

Thursday, July 28, 2022

Summer sale: 3 for 10€

In the evening, I went to bookshop Broekhuis and found out that it was the last week of the summer sale during which each book costed only 5€ and three books 10€. These kinds of offerings always drive me mad, because when I have found two books that I want to buy, I always find it hard to find a third book that I like enough to be included. It often results me in not buying any book at all. I spend more than an hour going through all the books on sale to end up buying the following three books for 10€:

Friday, July 29, 2022

Wind direction graph

Today, I read the copyrigcht page of the website of the Royal Netherlands Meteorological Institute and noticed that it has a CC0: Zero / public domain license. So, I do feel no problem to create a copy of the Weer- en klimaatpluim en Expertpluim page that shows the improved wind direction graph.

This months interesting links

Home | June 2022 | August 2022 | Random memories