Evaluate a Bspline and its derivatives.
Given the knots and coefficients of a Bspline representation, evaluate the value of the smoothing polynomial and it’s derivatives. This is a wrapper around the FORTRAN routines splev and splder of FITPACK.
Parameters :  x (u) – a 1D array of points at which to return the value of the :
tck – A sequence of length 3 returned by splrep or splprep containg the :
der – The order of derivative of the spline to compute (must be less than :


Returns :  y – an array of values representing the spline function or curve. :

See also
splprep, splrep, sproot, spalde, splint, roots, integral, bisplrep, bisplev, UnivariateSpline, BivariateSpline
References
[R5]  C. de Boor, “On calculating with bsplines”, J. Approximation Theory, 6, p.5062, 1972. 
[R6]  M.G. Cox, “The numerical evaluation of bsplines”, J. Inst. Maths Applics, 10, p.134149, 1972. 
[R7]  P. Dierckx, “Curve and surface fitting with splines”, Monographs on Numerical Analysis, Oxford University Press, 1993. 