ILNumerics.Toolboxes.Interpolation (nuget): Efficient n-dimensional interpolation routines for gridded and non-gridded data. Free trial licenses are available here: https://ilnumerics.net/download.html.
Keywords: ILNumerics|Computing|spline|n-dimension|interpolation|polynomial|Math|Arrays|FFT|LAPACK|numpy|Matlab|Visualization|Plotting|Charts|3D|High|Performance