When the configuration of a circuit and the equivalent representations of the transistors are known, a computer program can be written to yield the performance of the circuit and the mean values of the circuit parameters. Nonlinearity of the transistors is accounted for by piece-wise linearization of an equivalent circuit. Rules of interconnection have been devised to combine this procedure efficiently with the manipulation of the matrix equations that define the linear extemal circuitry. The general method can be extended to combinations of basic circuits.