cubic spline

cubic spline

[′kyü·bik ′splīn] (mathematics) One of a collection of cubic polynomials used in interpolating a function whose value is specified at each of a collection of distinct ordered values, Xi (i =1, …, n), and whose slope is specified at X1 and Xn ; one cubic polynomial is found for each interval, such that the interpolating system has the prescribed values at each of the Xi, the prescribed slope at X1 and Xn, and a continuous slope at each of the Xi.