This choropleth maps weekly influenza case counts across French regions for 2014, coloring each region according to its cumulative yearly total. The visualization uses d3.geoConicConformal to project regional boundaries from a GeoJSON file and d3.scaleQuantize to assign fill colors based on data loaded from a CSV file. The code demonstrates layering geographic shapes with tabular health data through D3’s data-join method, though the current implementation only sets the path fills without explicitly binding the CSV values to the regions.