Cubic Spline Interpolation, references & credits: https://github.com/barakman https://www.math.ntnu.no/emner/TMA4215/2008h/cubicsplines.pdf
Cubic Spline Interpolation, references & credits: https://github.com/barakman https://www.math.ntnu.no/emner/TMA4215/2008h/cubicsplines.pdf