Fork of Old Faithful HeatMap
This interactive visualization presents the Old Faithful dataset as a 2D heatmap, showing the relationship between eruption durations and waiting times. The plot uses a binned rectangular mark, with color intensity representing the count of observations in each bin, rendered using Vega-Lite’s `bin` encoding and `aggregate: "count"`. The code employs a minimal setup with D3.js to fetch the TSV data and re-renders the visualization on every mouse movement, dynamically adjusting the bin count via `Math.round(bins)`. Consequently, the heatmap’s granularity responds directly to the horizontal cursor position, letting viewers explore different binning resolutions. The visualization relies on vega-embed to render the specification as a static SVG.