1. A method for determining a value for a control variable for an engine, comprising the steps of: obtaining a plurality of pairs of programmed timing values for intake valve opening and exhaust valve closing in a cylinder of said engine responsive to a speed of said engine and a load on said engine, each pair of said plurality of pairs of programmed timing values based on a different one of a plurality of sets of predetermined operating conditions for said engine; obtaining a plurality of conditional values for said control variable, each conditional value of said plurality of conditional values responsive to said speed, said load, and a different one of said plurality of pairs of programmed timing values; determining said value for said control variable responsive to said plurality of conditional values for said control variable.