In a data processing system, a method for implementing a factor graph having variable nodes and function nodes connected to each other by edges includes implementing a first function node and a on a first computer system, the first computer system being in network communication with a second computer system; establishing a network connection to each of a plurality of processing systems; receiving, at the first function node, soft data from a variable node implemented on one of the processing systems, the soft data including an estimate of a value and information representative of an extent to which the estimate is believed to correspond to a correct value; and transmitting, from the first function node to the one of the processing systems, soft data representing an updated estimate of the value.