This is a stacked bar chart with slider dependent transitions. Uses D3.js V4
forked from reinson's block: Stacked bars & slider
https://d3js.org/d3.v4.min.js
https://d3js.org/d3-color.v1.min.js
https://d3js.org/d3-interpolate.v1.min.js
https://d3js.org/d3-scale-chromatic.v1.min.js