visualization Archives - Page 4 of 4

by virostatiq - April 17, 2013April 11, 2014

Noise pollution caused by church towers in Ljubljana

One Sunday I woke up to incessant and very loud tolling of nearby church bell. It was 9 o’clock in the morning. It didn’t seem fair that an institution can cause so much noise so early. As I work hard during the week, run almost every day, and write software, sometimes until late, I would very much prefer to sleep. The clergy would probably say that honest Christians are already awake at that time, so I’m no good anyway.

I then decided to research the matter. A number of facts surfaced, the most startling of which is a state decree, which states that church bells are not categorized as noise. If an inspector came to my house, measured sound levels while this was going on, and found out that they exceed proscribed levels, he would not be able to fine the aforementioned institution. He would probably bill me for the expenses of his time. But I digress.

Action was taken: city geometry was imported into computer along with church bell coordinates. Aggregate sound pressure for each building was calculated, then ranged so it could be visualized. Additionally, a point where there is least such noise was calculated. You can see results below. The point with least noise is on the green marker in the lower left corner. Lucky owner of that house.

Note: please notify me before embedding this map in your page.

I have to admit that the calculation is naive. It doesn’t take into account the elevation model, neither it accounts for building heights. Sound reflection is also ignored. But my curiosity was satisfied. I do live in the red zone.

Here are same maps on different scales. One is for entire country of Slovenia.

Edit: after this post went viral and other media (Dnevnik.si) published their own versions linking to me, I feel compelled to clarify my position about church bells. Personally, that is, as a person, and not a member of any organization, I’m bothered by long intervals of loud tolling on Sunday mornings. I’m told by other people they don’t like that either, and some other people point out that any attempt at playing music at this volume at similar hour of day would not end well.

I do somewhat like single chimes announcing hours of day, even at night. It’s a part of urban environment, and I’d probably subconsciously miss it should they quit. I’m not against Catholicism, the Church, or faith of any denomination.

When you toll so loudly next time please consider:

do unto others as you would have them do to you,
would Christ approve of that?

Thanks.

by virostatiq - April 5, 2013April 11, 2014

City visualization in Processing with rudimentary traffic simulation

Interactive traffic simulation made with Processing. GIS data of Ljubljana, Slovenia is read into RAM and converted into a vertex buffer object (VBO) with GLGraphics library.

Then a directed network graph is constructed from road data using JGraphT library. Cars are initialized, and a list of routes is generated with a Dijkstra shortest path algorithm. Then cars are assigned a random route and set on their way. When a car reaches destination, it’s removed from the list, and a new car is spawned.

Video:

Whole sketch with data is here for download. I used Eclipse and then transferred it to Processing, so there are pure Java classes in it.

You will probably have to run it in 32-bit Processing 1.5.1. It won’t work on Processing 2.0, because there have been significant changes with OpenGL. There’s also a possibility it won’t run on 64-bit Processing because of JGraphT library. I had one such report.

My other project with GlGraphics here.

by virostatiq - April 4, 2013April 11, 2014

How the social network of Hollywood actors evolved over time

This is a short update on previous post, which is a static visualization of relatedness between movies, genres and tags, as seen on IMDB. It’s produced from the same dataset of around 15,000 films, grabbed from IMDB.

It shows the social network of actors and its growth and changes over time.Every movie was analyzed, and a network constructed such that actors that worked together in a movie are connected. This connection also has a time dimension, so from first time when two actors have first seen each other, the network considers them as friends. Of course the actors have their own creative preferences, so they work with other people over time, so they move around the space – at first they are associated with one group, then with another.

The video below shows the animated network, as it evolved from 1960 to 2013. Only actors with more than 100 connections are shown.

It’s interesting to follow Robert De Niro’s associations. He starts off center, moves to center and then separates himself from the majority along with select other actors, which might be some kind of Hollywood elite.

Also note how Christopher’s career flowers and then wanes, as the century comes to a close.

Drop me a note in comments, if you want a bigger or more detailed visualization. This one was made with Gephi and some heavy processing and filtering before that.