Geo Word Clouds for geographic data visualization

During my Erasmus exchange at the TU/e, I was able to experience publishing a paper for the first time. I worked with my two teammates Daan and Jules on a data visualization project, which was started as part of the Algorithms for Geographic Data class.

Our work, under the supervision of professors Kevin Buchin and Bettina Speckmann, has been focused on creating word clouds with geographically accurate information. We have called them geo word clouds. The project ended with the preparation of a paper, which was presented at the 2016 IEEE Pacific Visualization Symposium (PacificVis):

Geo word clouds
K. Buchin, D. Creemers, A. Lazzarotto, B. Speckmann, J. Wulms

Word clouds are a popular method to visualize the frequency of words in textual data. Nowadays many text-based data sets, such as Flickr tags, are geo-referenced, that is, they have an important spatial component. However, existing automated methods to generate word clouds are unable to incorporate such spatial information. We introduce geo word clouds: word clouds which capture not only the frequency but also the spatial relevance of words. […]

Here you can see a map generated with our algorithm, written using Python and SageMath:

Kinds of cheese produced in France

The IEEE Copyright Policy explicitly grants permission for authors to share their papers on personal websites. For this reason, I am sharing the accepted version of the paper together with this notice:

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

You can read the full text PDF here.

How to get Evernote Premium for €20 ($22) a year

Evernote is a great note taking platform, which I covered before in this blog post. A few days ago, they announced a dramatic change to the pricing of their paid plans. In particular, the following changes occurred:

  • Evernote Plus went from $24.99/year to $34.99/year
  • Evernote Premium went from $49.99/year to $69.99/year
  • Evernote Free is now limited to two active devices

Criticism from users

These news unleashed quite a bit of discussion at the Evernote forum, especially because Plus and Premium users who have been paying for years don’t like a 40% increase in prices without any new feature.

Free users are also a bit upset because the philosophy of former CEO Phil Libin has not been respected:

The idea is that we want you to use Evernote forever. Once you’re using it, we want you to keep using it, and it’s more important that you stay than you pay us. We want the engagement. The longer you use it, the higher the perceived value gets. And the higher the perceived value, the more willing you’re willing to pay. It’s up to us to make something that you want to pay for. The percentage of people who pay in the first month is like one half of one percent. But if they use it for a year, that goes up to seven percent. In the second year, it goes up to 11 percent. Our oldest cohort, the people who have been with us five years or so, it goes up to 25 percent.

Of course, some say that free users are only a cost so their opinions are not important, but Phil Libin has been pretty good at explaining the opposite. The strict limit of two devices will break the flow of new users (and potential clients).

I have been a Free, a Plus and a Premium user at different points, hence I understand the concerns of all users.

Different prices in different countries

The Evernote announcement contained a huge hint to something I didn’t fully realize before, i.e. that “regional pricing may vary”. Initially, I though of obvious small differences related to different currencies and rounding numbers. For example, Premium costs $70 in the USA which roughly corresponds to €63. The price in Italy is €60, but it is more or less the same.

This forum post by a Brazilian user revealed that there’s more than meets the eye:

I would NOT pay US$ 70 / year to keep using Evernote, but the Plus subscription here in Brazil is quite affordable, so I’ll keep using Evernote

This is interesting!

Evernote accepts PayPal payments, but only for supported currencies. Unfortunately, PayPal only allows Brazilians to pay using Brazilian Real as a currency. Therefore I took the time to use several servers of the VPN service I use daily, to check prices in the countries listed on the PayPal page.

I discovered that Evernote prices vary a lot between countries. This table shows how much Premium costs in some of the countries where Evernote is cheaper than the USA. The amounts in euros are rounded and those in US dollars are derived from them:

Country Price in EUR
Price in USD
(assuming €1 = $1.11)
Russia € 28,00 $31,08
Taiwan € 38,00 $42,18
Mexico € 19,00 $21,09
Israel € 37,00 $41,07
Poland € 22,00 $24,42
Singapore € 38,00 $42,18
Japan € 45,00 $49,95
Brazil € 22,00 $24,42
Hong Kong € 41,00 $45,51

Basically, a Mexican Premium account has the same features but it costs a third of an American one.

Buying the subscription

I tried to buy a year of Evernote Premium at the Mexican price and I confirm it works. The idea is simple: anyone can use a VPN service to connect to Evernote through a Mexican IP address and pay the 399MXN price.

Therefore, you will need one that supports Mexico. I have written about some VPN services (both free and paid) in the past, but you can actually use any as long as they provide you a server in Mexico. Many commercial VPNs offer a free trial and you only need the service for 10 minutes. 😉

Once your VPN connection is active, head over to the Evernote pricing page and you will see the prices in Mexican Pesos. You can proceed to activate your account and pay through PayPal:

Buying a year of Evernote Premium for €20
Buying a year of Evernote Premium for €20

PayPal will also set up an auto-renewable subscription with the Mexican price, so you don’t need to repeat the process if you plan to buy the subscription again. Finally, you need to wait for a few minutes.

You will receive a confirmation email from Evernote telling you that you that your profile has been switched to Premium. That’s it, you don’t need the VPN anymore. 🙂

Coffee at TU/e

Daria Nepriakhina --- Unsplash
Daria Nepriakhina — Unsplash

For many university students, coffee is an essential fuel to stay focused and productive. Moreover, being an italian, my goal was to find a decent espresso also at TU/e.

There are basically two available options: the canteen and the vending machines.

In the several TU/e canteens, there is a bit of discrimination: the Dutch “coffee” (dirty water) 😛 costs 0.45 €, whether an espresso costs as much as 1.25 €! Moreover, the coffee is provided in paper glasses. They are really cute but they ruin the taste of coffee.

At the vending machines all kinds of coffee cost 0.45 €. Coffee is provided in a plastic glass but without a scoop for mixing the sugar. Moreover, the machines look similar but options differ depending on the building.

In MetaForum you can choose to have a coffee with sugar or black, but it’s not possible to choose the amount of sugar or the intensity of coffee. In Auditorium, instead, you can tune both parameters. Anyways I advise against selecting the “espresso white” because it’s a macchiato of very bad quality.

Given the price difference and the plastic glass, the conclusion is easy: buy the espresso at the vending machine and not in the canteen!

Stickers for advertising and garbage collection in Eindhoven

Some days after I moved to Eindhoven, I went to the city hall to register as a resident. I took the chance to ask questions about two problems related to the house: advertising into the mail box and garbage collection.

After some days, you may start to get many advertisements (obviously in Dutch) by mail. To defend yourself from this “invasion”, it is necessary to get a sticker. There are of two kinds: the Nee Nee e the Nee Ja. This Dutch website explains how they work:

Nee Ja
Nee Ja

With this sticker you won’t get any advertising, but you will get some house-to-house newspapers.

Nee Nee
Nee Nee

With this sticker you won’t get any advertising nor house-to-house newspapers. You may ask for the stickers at the city hall and you will get them for free. I advise you to do so as soon as possible!

Regarding the garbage collection in Eindhoven, there is a great website called Afvalkalender (garbage calendar). You have to insert your postcode and you can see the days in which they are collected. Where I live there is only collection of paper, generic waste is thrown in the dedicated containers that are opened with the magnetic card. Glass needs to be thrown into the bins close to supermarkets.

A quite unusual thing is that collection does not necessarily happen in the morning. Yesterday they picked up paper at 6pm!

TU/e email: parameters for IMAP, POP and SMTP

Every TU/e student has an email box with a address. It is possible to open the inbox directly from the webmail in OASE, however it may be preferred to use a client.

IMAP technology allows to connect many devices to the inbox, including PCs, smartphones and tablets. In this way you can receive emails without the need to open the OASE website. Less recent clients can use POP to receive mail, without syncronization of read messages.

Unfortunately, the parameters for IMAP, POP and SMTP are spread across different web pages. For example, this page contains only SMTP parameters. The Outlook Web App interface instead contains correct data for IMAP and POP but not SMTP.

For this reason, I sum up all the data here. They are updated to February 2015.


  • Server:
  • Port: 993
  • Security: SSL/TLS


  • Server:
  • Port: 995
  • Security: SSL/TLS


  • Server:
  • Port: 587
  • Security: SSL/TLS

Username and password correspond to those of OASE. This may cause problems with some software. For example, the wizard of Thunderbird uses the same server for the email address and the IMAP connection, so it may be mislead by However, it’s possible to modify the account by hand to correct the problem.

Finally, there is one thing to say regarding the possibility of forwarding emails to another address. Forwarding is useful for those using interfaces such as Gmail. To receive, you set up the TU/e inbox to forward messages to Gmail. To send, you set up Gmail to use the TU/e SMTP server.

The problem is that forwarding is possible only with the new interface of Outlook Web App, but sometimes the website shows the old one. In that case, you can try to change browser to create the filter. More information about supported browsers is available here.

The examination calendar at the DTU

At the end of the semester in which I studied at the DTU, I needed to find information about exams. The dates are decided well in advance, but the times and the place are told only a few days before.

At the beginning I was a bit afraid, then I was able to find everything. I discovered that the most important information about exams is given only in Danish. For this reason, I want to give some advice to those who are in the same situation.

There’s nothing worse than knowing the day of an exam, but not knowing where it will be. Look at the difference between the page in Danish and the one in English:

While I am writing this post, the page in Danish contains a notice:

Lokaleoversigt og tider for eksamen vil være tilgængelig en ugen inden eksamensperioden begynder på “Infosite for studerende” (kun tilgængelig for ansatte og studerende).

The meaning is:

Exam rooms and timetables will be available one week before the exam periods starts in the «Infosite for students» (only available for personnel and students).

The link sends you to Portalen.

As you have seen, the “magic word” is lokaleoversigt. In particular you can search:

  • Lokaleoversigt for vintereksamen for winter exams
  • Lokaleoversigt for sommereksamen for summer exams

The new version of the DTU website also contains a section called undervisnings lokaler. It allows to search rooms for classes and exams.

Written exams examples for Computer Science Modelling

It seems that at DTU it is not common to give some examples of old written exams to the students. Given that I attended the Computer Science Modelling course, I was able to access a “fake” exam and I scanned a copy of the real examination I did in June 2013. As a bonus, I used an OCR software (article in Italian) to make the PDF searchable. 😉

The top 10 applications for exchange students

Being students means to have to handle many things and all different: it is necessary to coordinate studying and amusing and being able to do it in a simple and fast way. This is especially true when you are abroad and there are more things to do than usual.

As you know I spent January in Aabenraa in order to learn a bit of Danish, and now I attend the university in Lyngby. In these two months I have been able to observe some tools that are used by my peers, as well as to talk and exchange tips about that.

I noticed that virtually all of us use more or less the same programs for our students’ routine because the laptop is a fundamental component not only for studying, but also for communicating. What matters most is that most of my friends don’t study IT, so I saw with my eyes the “normal” use of the computer as a tool and I decided to write this list of 10 applications.

As you will see, they are almost all web 2.0 services, for productivity or communication. The list is a “mix” between what I have seen to be used by everybody and some tools that I use and I would like to suggest. Put these 10 programs and services in your virtual luggage and you will be perfect exchange students. 😉

The common aspect of all the points in the list is only one: convenience. The average student does not have much time to waste, doesn’t need super-advanced features, wants to manage everything with a few clicks. For sure you already know some of the things I will list, but I would like to know why and for what we use them.

1. Ubuntu

ubuntuIt’s true, I start immediately with something that not everyone uses, but in my opinion it’s a pity. 😛 Ubuntu is an operating system alternative to Windows or Mac OS X. It’s fast, free and without viruses.

I think it’s ideal for students because it’s modern interface is designed for the daily tasks that all students do: surfing the net, chatting, writing documents, creating presentations, listening to music, watching a movie. All of this in an extremely covenient way and with the possibility to install thousands of software with a click. Try it!

Official site
Guided tour

2. Google Chrome

chromeThere are some browsers that are more widespread than others, but I was surprised to see that 90% of the students I have met use Google Chrome. It’s a quite high percentage!

I have always used Firefox, but I tried to think why Chrome is so common. Finally I understood that it’s because of its convenience. The fact that Firefox is more powerful and extendable for specialized tasks is not important, what matters to many is just that the browser loads quickly.

The fact of having an integrated PDF reader is another advantage. Personally I started to use Chromium because it is its open source version, but now I have installed Chrome for its PDF support and the flash player that works a bit better.

Official site

3. Dropbox

dropboxThis web service gives 2 GB of free space in the cloud, that can be easily extended by inviting friends to join. You can have access to your files safely using the web interface and automatically synchronize them with the client for all operating systems and for mobile devices.

In addition to synchronization, it also gives you the automatic backup of files up to 30 days before: if you delete or edit a document by accident, recovery is just a click away! Also, the sharing features are very useful. The best thing to do is simply creating a University folder in Dropbox and saving everything in it.

Official site

4. Evernote and Clearly

evernoteIt’s difficult to exactly define Evernote. It isn’t only a website in which you can write notes, but it also includes a client software for Windows and Mac (under Linux I use the web interface and I am fine), apps for phones and tablets and extensions for the browser. Notes can be divided in notebooks — for instance one for your documents and one for every class you follow — and labeled with tags.

The real potential of Evernote shows up when you use it along with the two official browser extensions. The first is called Web Clipper and allows you to “clip” a part of a webpage and save it with one click inside Evernote, when it immediately becomes indexed and searchable.

clearlyThe second extension is called Clearly and allows you to have a readable and distraction-free view of any articles you find online. The extension isolates the important content and eliminates all the rest, allowing also to save the page in Evernote and automatically deciding the most relevant notebook.

The Evernote extensions for Chrome work a bit better than the Firefox ones, and it’s one of the reasons for which I switched to Chromium at the beginning. I use them to save all the documents related to my Erasmus, as well as pieces of Wikipedia pages or other information that can be useful for studying. Probably I will write a more deep article and I will give you more details. 😉

1 month of Evernote Premium for free
Web Clipper

5. Wolfram|Alpha

wolframalphaAt first sight it may seem that this computational search engine is useful only for people studying maths, computer science or engineering. It’s true, You can perform very complicated computations with it, but that’s not all!

Wolfram|Alpha includes search functions for many other fields: statistics, geography, chemistry, music, linguistics, astronomy, earth sciences, medicine… the list of examples is very long. I have been using this site from where I was in the last years of high school and I can guarantee that it is very useful.

Official site
List of examples
Guided tour

6. DuckDuckGo

duckduckgoWhat would you think if I told you that my favorite search engine is not Google? Just so, most of the times I use DuckDuckGo, a very convenient search engine that gives a very useful feature: the instant answer.

When you search for something that can cleary be found on Wikipedia, StackExchange, Wolfram|Alpha, Twitter or many other sites, DuckDuckGo shows it to you as the first result in a highlighted box. This saves a lot of time.

Also, if you don’t like DuckDuckGo results you can simply ask to search using another service: just add a “!bang” to the search query: for example !google, or !yahoo, or !maps, or !youtube, or… well, you got it. 😛

Official site
Introduction video
List of !bang shortcuts

7. Facebook

facebookSome love Facebook, others hate it. Many use it to “waste time” between games and funny pictures. The reality is that this social network reveals its real usefulness when you are abroad, I noticed especially after the Danish course.

Facebook is fundamental for keeping in touch with friends in your country and the “colleagues” that then spend the Erasmus in other cities. By living abroad you will end using Facebook for silly things (if you are already members) and you will start to use it for what it was designed: communicating, staying updated about events and handling your network of friends.

Official site

8. Skype

skypeOf course going abroad means keeping in touch with people in your own country. There are many VoIP services, but Skype is for sure the most famous of all. It allows you to perform free chats, calls and videocalls through the Internet using a computer or smartphone.

In addition to this, if you are in need, it gives a low cost call service to landlines and mobile phones. Ironically from when it has been bought by Microsoft it has had a more updated Linux version, not bad!

Official site

9. Spotify

spotifyGiven that it recently launched also in Italy, I think it’s the best moment to talk about it! Spotify is a music application that combines social features with a huge songs library. The best thing is that by using the program and an Internet connection you can listen to millions of tracks for free.

There are some limitations on how much monthly hours you can use and some advertisements, but they absolutely don’t give hassle and you can exactly choose which songs to play, skipping from one point to another in any moment. if you are in one of the 24 countries where it is available, try it and you will not regret!

Official site

10. Rejseplanen

rejseplanenThis application is dedicated to those living in Denmark, but I am sure that there exist some similar in many countries. In general, you should search a service that allows you to search the trains and buses you need in the country where you study.

Rejseplanen allows to set two arbitrary addresses of departure and destination and shows some suggested connections, with the possibility to see the tariff zones in which Copenhagen is divided. If you don’t live in Denmark you can try the site and the application of the German railways, containing the routes of all Europe.

Official site
DB Bahn (trains across all Europe)


It’s obvious that everyone chooses and uses the tools that he/she likes most, but I tried to write a generic list including applications and web services that can be useful to the majority of exchange students. What other tools do you suggest? Write them in the comments. 😉