Implements an activity heatmap, which shows activity levels on a calendar. An example is shown below:

Example usage in index.html. The code segment that initialises the activity heatmap is as follows:

        d3.csv("dji.csv", function(data) {
            var activityMap = new ActivityMap(data, {
                "id": "dji-volume-map",
                "parent": "#activitymap-container",
                "title": "Dow Jones Index - Trading Volume ",
                "timeColumn": "Timestamp",
                "valueColumn": "Volume"
        });
        activityMap.render();

The API call takes the form:

        var activityMap = new ActivityMap(data, config);

Where config can have the following attributes:

• compact: If true, activity map displays entire year in one band. If false, days are grouped into months. Compact mode is chosen by default. See index.html for example.
• id: DOM identifier to use for the activity map.
• parent: The container DOM node. You can either specify a D3 node, or a CSS selector.
• title: Title to use at the top of the activity heatmap. The year range that is visible will be displayed as a suffix.
• timeColumn: In the input CSV data file, which column should we use to get the activity timestamp. The time in data is specified either as an integer that represents the Unix timestamp in milliseconds, or as a JavaScript Date() object.
• valueColumn: In the input CSV data file, which column should we use to get the value to be used as heatmap value.
• colours: Array of colours that should be used to represent activity intensity. This is calculated according to the heatmap value relative to the maximum heatmap value in the data set. These colours should be specified as a gradient starting with the colour for the lowest value, and ending with the colour for the highest value.
• fit: Optional parameter that allows the resizing of the activity map. By default, the activity map will exists inside the supplied container. To make the container fit the activity map, set fit to true. See index.html for example.
• hue: Optional parameter that sets the Hue for the cell colour gradient. The value should be in the closed interval [0, 360]. By default, Hue is set to 85.

If the config is unspecified, the following values will be taken by default:

• compact: true
• id: 'example-activity-map'
• parent: 'body'
• hue: 85
• title: 'Activity map: '
• timeColumn: 't'
• valueColumn: 'v'
• fit: false

The Dow Jones Index, trading volume data was taken from this d3js example.