Digital Geography

Awesome map style

Are you back from holiday? Maybe you switched from Casale Monferrato, Piedmont and have used the map of Monferrato Landscapes. If you were lucky, you see a new update, I’ve made ten days ago, otherwise I invite you to go to review … but before I tell you how it was created.

Short Announcement: Leaflet 1.0

Leaflet is one of a kind in the list of javascript webmapping libraries. It was designed with simplicity, performance and usability in mind. Unfortunately the development seemed to have stopped for a while. This week Vladimir Agafonkin (the creator of Leaflet) released a Beta version of Leaflet 1.0

Create custom markers with R for your webmap

When it comes to webmapping there are thousands of possible markers you can choose from but when it comes to markers depending on the data, which is inside the shapefile, possibilities are more limited. In leaflet you can define different icons according to the attributes of your data by defining the icon url in an attribute. Let me show you, how to use the data in each feature to create a custom icon like a piechart marker using R.

Create your own StoryMap

Have you seen “the story maps” created on the ESRI website (http://storymaps.arcgis.com) or for that matter from http://storymap.knightlab.com/ or http://mapstory.org/. They are all frameworks for you to create “a story” with geographic connections, and they achieve this more or less successfully. Common for all of the above are that they are services, depending on the on-line framework. This makes it possible to present a more user friendly experience when you create the story, but at the same time you loose some flexibility and you need to be on-line. Here I’ll show how you can build a storymap yourself based on…

The Spiegel Magazine and their “maps”

Today I stumbled upon a “map” on Spiegel Online ( an import news page in Germany ) which shows the spied countries of the NSA. As we already know leaflet quite good and also tried other mapping possibilities I was interested in what they are using for this map which is more informative than this useless map. So looking on the source code: It’s a library called jvectormap.

how to create clustered points in leaflet

The leaflet API is very simple and tries to deliver best performance and style for commonly used features like tilelayers, points and lines and markers in general. So when we would like to visualize points it is possible to have a very large numbers of points. So lets have a look on such an basic example. I’ve created a point shape file with QGIS which has approx. 1.000 points embedded. Let’s have a look on a normal webmap with this density of information: As you can see, we’ve inlcuded a second js file with the point information called points_rand.js. You…

Make it simple – How to add Line Simplifcation to your Web Mapping

When Mike Bostock published his (re-) implementation and demonstration of Visvalingams algorithm for line simplification he attracted considerable attention on that. What is a little bit strange in my opinion. This algorithm is old hat as like the second more well-known algorithm invented by Douglas-Peucker. Both can be seen as the basic concepts for the simplification of linear geometric objects when a quick & easy implementable point reduction is essential. And this is what they can achieve…reducing the amount of points, by analysing the topology of each point…not more but also not less! They are well-known and (relativ) easy implementable…

D3-Basics – All you need is a selection!

Since a while I am programming with the JavaScript library D3.js … and … I am addicted to it! As I would like to present some tutorials on D3’s fantastic possibilities to create and design webmapping solutions … I think it would be good to give you a description on the things that I would identify as elementary. Caution! This tutorial could be a little bit too detailled for you, when you are a skilled JavaScript programmer! I am sorry for that! But when you are a noob in JavaScript, as I was when I began to program with D3,…