API Reference > geometry-core > ArraysAndInterfaces > IndexedXYCollection > vectorIndexIndex vectorIndexIndex MethodAbstract Return a vector from the point at indexA to the point at indexB vectorIndexIndex(indexA: number, indexB: number, result?: Vector2d): undefined | Vector2d Parameter Type Description indexA number index of point within the array indexB number index of point within the array result Vector2d optional caller-allocated vector. Returns - undefined | Vector2d undefined if either index is out of bounds Defined in geometry3d/IndexedXYCollection.ts Line 46 Last Updated: 11 June, 2024