splineEval

The spline is represented as a matrix(-like object), where each row starts with l.h.s. end-point of the interval, and from the second element on, the polynomial coefficents are defined for the given interval. Technically it needs to be only a piece-wise polynomial, in particular [0 p] is technically a polynomial, where p is a usual polynomial.

import almafa.engine.func-1;


  s = [0, -1; 1, 2,0,0,0,0; 2, -1,0];
  x0 = [-1, 0, .5, 1, 1.5, 2, 2.5, 3];
  xmin = min(x0);
  xmax = max(x0);
  xeps = (xmax-xmin)/200;
  xmin -= 2*xeps;
  xmax += 2*xeps;
  x = xmin..xeps..xmax;
  [! x0; splineEval(s,#x0) !]
  plot(x,splineEval(s,#x))

s	The spline.
x	Evaluation point.

splineEval(s, x)