API Reference > geometry-core > ArraysAndInterfaces > IndexedXYZCollection > vectorIndexIndex vectorIndexIndex MethodAbstract Return a vector from the point at indexA to the point at indexB vectorIndexIndex(indexA: number, indexB: number, result?: Vector3d): Vector3d | undefined Parameter Type Description indexA number index of point within the array indexB number index of point within the array result Vector3d caller-allocated vector. Returns - Vector3d | undefined undefined if either index is out of bounds Defined in core/geometry/src/geometry3d/IndexedXYZCollection.ts Line 76 Last Updated: 13 June, 2024