This example shows a heatmap visualization of distances from a central point, computed from two arrays of numeric coordinates. The heatmap uses a Portland color scale and smooths the data with the `zsmooth: 'best'` option, rendering through Plotly’s `newPlot` API. The code constructs a matrix by calculating the Euclidean distance for each pair of x and y values, then passes it to Plotly’s heatmap trace. D3.js is loaded for potential utility, though the core rendering relies entirely on Plotly 2.16.1.