REDUCE

9.9 INTERPOL operator

Syntax:

INTERPOL(values,variable,metapoints);

where values and points are lists of equal length and <variable> is an algebraic expression (preferably a kernel).

INTERPOL generates an interpolation polynomial f in the given variable of degree length(values)-1. The unique polynomial f is defined by the property that for corresponding elements v of values and p of points the relation f(p) = v holds.

The Aitken-Neville interpolation algorithm is used which guarantees a stable result even with rounded numbers and an ill-conditioned problem.