These methods are used to set the sorting function for the primary and secondary parts.
The example on the left is using the default sorting functions for primary and secondary parts which is d3.ascending
.
The example on the right is using custom sort function for primary and secondary parts.
For other options and examples, check VizJS
Modified http://vizjs.org/viz.v1.1.0.min.js to a secure url
https://d3js.org/d3.v4.min.js
https://vizjs.org/viz.v1.1.0.min.js