HermiteCSpline
InterpolatingFunction.HermiteCSpline(x,y,m) creates a Cubic-Hermite-Spline with knots x, values y and slopes m (all tables of realvalues)
InterpolatingFunction.HermiteCSpline(x,y) creates a Monotone-Cubic-Spline where the slopes are chosen such that the returned function is monotonic if y is monotonic