Cubature formulas on combinatorial graphs

The goal of the paper is to establish cubature formulas on combinatorial graphs. Two types of cubature formulas are developed. Cubature formulas of the first type are exact on spaces of variational splines on graphs. Since badlimited functions can be obtained as limits of variational splines we obtain cubature formulas which are "essentially" exact on spaces of bandlimited functions. Cubature formulas of the second type are exact on spaces of bandlimited functions. Accuracy of cubature formulas is given in terms of smoothness which is measured by means of combinatorial Laplace operator. The results have potential applications to problems that arise in data mining.