In this chapter, I explained the usage of the most important statistical functions (such as d3.min() and d3.max()), and we saw them applied in the last example. They are useful to resize the axes and the chart automatically, when values in the dataset are out of the current range of the axis.

We also discussed array manipulation functions, which help us to modify, structure, and preprocess the data for the visualization. In the first section, we also saw an example of d3.nest() that groups elements as an associative array by their keys in multihierarchical levels.

You learned how to format number values and convert them to strings with d3.format(). The specifier defines how the formatter parses the values and formats them in different data types, currencies, and alignments.

Then, we introduced scales as a way to map an input domain to an output range. We saw linear scales for quantitative and ordinal scales as well as time scales, which are basically linear scales with JavaScript date...