API Reference > geometry-core > Bspline > BSpline2dNd > spanFractionsToBasisFunctions spanFractionsToBasisFunctions Method Evaluate basis functions given choice of u or v span index local fraction within the span. spanFractionsToBasisFunctions(select: UVSelect, spanIndex: number, spanFraction: number, f: Float64Array, df?: Float64Array): void Parameter Type Description select UVSelect spanIndex number spanFraction number f Float64Array df Float64Array Returns - void Defined in core/geometry/src/bspline/BSplineSurface.ts Line 331 Last Updated: 13 June, 2024