1. A circuit-based method for ranking nodes of a graph, comprising: providing a vector, in the form of a signal to a circuit, as a function of a set of random parameters wherein the vector represents a probability distribution on the nodes of the graph and can solve a linear system; using a probability matrix function based upon a Markov chain on the graph and relative to the nodes of the graph to assess statistics of the vector for solving a probability-based system that is based on the vector and based on a non-deterministic variable; and ranking the nodes of the graph based upon the assessed statistics of the vector.