API Reference > geometry-core > CartesianGeometry > Point2dArrayCarrier > vectorIndexIndex vectorIndexIndex Method Return a vector from the point at indexA to the point at indexB vectorIndexIndex(indexA: number, indexB: number, result?: Vector2d): Vector2d | undefined Parameter Type Description indexA number index of point within the array indexB number index of point within the array result Vector2d caller-allocated vector. Returns - Vector2d | undefined undefined if either index is out of bounds Defined in core/geometry/src/geometry3d/Point2dArrayCarrier.ts Line 66 Last Updated: 15 June, 2021