d3 point locator
This example demonstrates how to locate the y-coordinate of a point on a smoothed curve for a given x-value, using a bisection algorithm on the SVG path element. It generates a random walk dataset of 50 points, renders it as a smooth line using d3.line with the “curveBasis” interpolation, and then for each data point, finds the corresponding y-value on the rendered path by repeatedly sampling path.getPointAtLength. The code uses d3.select, d3.scaleLinear, and d3.line to create the visualization.