Heatmap is the latest chart addition in Highcharts 4. As its name implies, the data values are represented in temperature colors, where the data is arranged in a grid-based layout, so the chart expresses three-dimensional data. The heatmap appeals to some readers because of the instant awareness of the data trend it generates, as temperature is one of the most natural things to sense. The chart is generally used for demonstrating climate data, but it has been used for other purposes. Let's explore the heatmap chart with some real-life data. Here, we use it to show the inflation of various countries, as in this example in the Wall Street Journal (http://blogs.wsj.com/economics/2011/01/27/feeling-the-heat-comparing-global-inflation/):

In Highcharts, the heatmap module was released as part of the Highmaps extension, which can be used as part of Highmaps or as a module of Highcharts. In order to load a heatmap as a Highcharts module, it includes the...