This example shows a 10-by-10 heatmap of categorical data, where each cell’s fill pattern encodes a numeric value instead of color. Four texture patterns with different circle sizes are mapped to value ranges via a `d3.scaleOrdinal`. The chart is built with D3 v4, using `d3.scaleBand` for axes and SVG `<rect>` elements for cells. Data is loaded from a remote CSV file, and textures are generated with the textures.js library.