g functions fp 1 fp 2 in fig3 a to some or all of the sets of operational parameter values that reference the performance parameter values and or can apply a preconditioning function e g the inverse of function fv 1 in fig3 e to the performance parameter values the preconditioned data is then passed to mathematical model generator 450 which fits mathematical forms to the performance parameter data or preconditioned performance parameter data as referenced by the preconditioned and any non preconditioned operational parameters thereby generating the mathematical models e g function fm 1 in fig3 a or function fm 6 in fig3 e for the cells in the final characterized cell library 460 mathematical model generator then writes the characterized cell library 460 to some form of computer readable medium such as memory within computer system 400 a removable storage medium e g cdrom or dvd or a network storage location note that according to another embodiment of the invention writing the final characterized cell library to some form of medium can be performed outside of library generator 420 e g in a separate software module or even a separate computer system note that as indicated by the double headed arrow between preconditioner generator 440 and mathematical model generator 450 if the modeling.