A choropleth map of French regions visualizes weekly influenza case counts across 52 weeks in 2014, with a slider to navigate through time. The map’s fill colors are assigned from a five-step quantize scale based on the selected week’s value, and hovering over a region shows a tooltip with its name and count. Built with D3 v4, the visualization binds CSV data to a GeoJSON topology, renders regions using `d3.geoPath` with a conic conformal projection, and updates the `style.fill` dynamically on slider input.