This example visualizes daily temperature data for three U.S. cities—New York, San Francisco, and Austin—as a multi-line chart over a date range from October 2011 to January 2012. Built with D3 v4 and rendered as SVG, the chart uses color-coded lines to compare temperature trends across the three cities, with a date-based x-axis and a temperature y-axis. The dataset, loaded from a TSV file, contains 100 days of observations for each city. The visualization serves as a starter template for a finite element method (FEM) exercise, providing a clean, minimal foundation for further interaction or analysis.