package owl-base

``polint xs ys x`` performs polynomial interpolation of the given arrays ``xs`` and ``ys``. Given arrays ``xs0..(n-1)`` and ``ys0..(n-1)``, and a value ``x``, the function returns a value ``y``, and an error estimate ``dy``. If ``P(x)`` is the polynomial of degree ``N − 1`` such that ``P(xsi) = ysi`` for ``i = 0,...,n-1``,

Parameters: * ``xs``: an array of input ``x`` values of ``P(x)``. * ``ys``: an array of corresponding ``y`` values of ``P(x)``. * ``x``: value to interpolate.

Returns: * ``(y, dy)`` wherein ``y`` is the returned value ``y = P(x)``, and ``dy`` is the estimated error.

TODO