communicating with data
What is a map? before we start looking at the code it may be a good idea to think of the best way to represent a country. Countries are areas of land surrounded by borders, which are imaginary (or sometimes physical) lines going through a set of points. Some countries are made of one of [...]
This week, I was made aware of a new set of maps by French ministry of Foreign Trade, called cartographie de la France qui exporte (map of France exports) (link). Since I’m interested in the topic and that I know that French public services have killer cartographers I was eager to see what was so [...]
previous: reshaping complex arrays (4/5) Working with layouts In this final part, we’re going to look at how we can shape our data to use the protovis built-in layouts such as stacked areas, treemaps or force-directed graphs. This is not a tutorial on how to use layouts stricto sensu, and I advise anyone interested to [...]
Previous: array functions in javascript and protovis Reshaping complex arrays This really is what protovis data processing is all about. In today’s tutorial, I am going to refer extensively to protovis’s Becker’s Barley example. One reason for that is that it’s also used in the API documentation of the methods we are going to cover, [...]
We are taking a look at the Protovis Becker’s Barley example. Data: The code begins by defining a function that will be used throughout the program. this function expects an array of associative arrays which have the key “yield”. What it does is that it returns the median of all the values of the key [...]
Protovis, like Tableau, are based on the grammar of graphics framework. In a nutshell, in both environments, a chart designer can map visual attributes (such as x or y dimension, color, shape, etc.) to dimensions of data. The flat file which Becker’s Barley is based on can be used in Tableau public nearly as is. [...]
Previous : Multi-dimensional arrays, inheritance and hierarchy Short interlude: what can be done with arrays in javascript? Now that we have a grasp on how arrays work and how they can be used in protovis, let’s take a step back and look at some very useful methods for working with arrays in standard javascript. Sorting [...]
Previous post: simple arrays Multi-dimensional arrays, associative arrays and protovis Even for a simple chart, chances are that you’ll have more than a single series of numbers to represent. For instance, you could have labels to describe what they mean, several series, and so on and so forth. So, let’s say we want to add [...]
When I started using protovis I had only a very basic knowledge of javascript, which in theory isn’t a problem as protovis is meant to be learned by example, and as it has its own logic and structure which is different from typical javascript code. So I started by looking and modifying examples which was [...]