The function that splinefun and splinefunH return: the spline, or a derivative, at the points xq. The order of the derivative is the second argument or the option deriv (giving both is a RangeError).
xq
deriv
The spline at xq, or its derivative of order deriv (0 to 3).
Optional
The spline at xq, with the order of the derivative in the options: s(xq, { deriv: 1 }).
s(xq, { deriv: 1 })
The function that splinefun and splinefunH return: the spline, or a derivative, at the points
xq. The order of the derivative is the second argument or the optionderiv(giving both is a RangeError).