In univariate interpolation, an interpolant is a function L = L(x) which agrees with a particular function f at a set of known points x_0, x_1, x_2, ..., x_n and which is used to compute values for f(x) at points x!=x_i, i = 0, 1, 2, ..., n. Modulo a change of notation, the above definition translates verbatim to multivariate interpolation models as well.