Quantitative data visualizations that employ dots, lines, and other shapes to represent values usually need to situate those values within the context of a domain. The most common way to provide this context is using axes. Each axis represents a data domain, providing lines, tick marks, and labels that are rendered in the same scale as the data points. One axis represents one dimension. The Cartesian system, which used in most bar, line, area, and scatter charts, employs two perpendicular axes that provide context for a two-dimensional space. Other visualizations may use three or more axes.
The d3-axis module contains ready-to-use one-dimensional SVG axes that you can attach to a scale, configure, and use to assemble linear, Cartesian, and radial grids. In this chapter, you will learn how to use it to create axes for your charts, configure position, ticks...
