This example demonstrates d3-brush with custom resize handles in D3 v4, highlighting the brush selection over a scatterplot of 800 random points. It shows how brushed points become highlighted with a red stroke, while custom path-based handles render on the left and right edges of the selection. The implementation uses d3.brushX, d3.scaleLinear, and d3.axisBottom, with the handle path defined via a custom function resembling the crossfilter approach. The brush’s start and brush events trigger the brushmoved function, which updates point activity and handle positioning based on the current selection.