Smoothed D3.js Radar Chart
This smoothed radar chart visualizes energy-related data, showing how intensity values vary across different sectors. The chart uses filled, semi-transparent areas with rounded strokes for each sector, overlaid on circular grid lines with percentage labels. A legend identifies each sector by color. Built with D3.js version 3, the visualization loads `data.json`, computes average values for sorting, and uses a linear radius scale to map data points onto the radar axes. The implementation includes a glow filter and tooltip support for enhanced interactivity.