1. A method for creating a simulation file for simulating an analog circuit having an unknown circuit parameter, the method comprising: receiving, by a processor, as inputs to a circuit simulation program executed by the processor, values of individual components of an analog circuit and respective interconnections of the individual components, for creating the simulation file of the analog circuit, wherein the respective interconnections are represented by nodes within the simulation file, wherein a first value of a first component of the individual components is an unknown circuit parameter of the analog circuit; determining, by the processor, based at least partially on component types of the individual components, that a second component of the individual components is a nonlinear component; obtaining, by the processor, from a database of mathematical models for nonlinear components, a direct current (DC) mathematical model corresponding to the component type of the second component; determining, by the processor, a linear function for the second component for at least a portion of an operating range of the second component to substitute for the second component in the simulation file; generating, by the processor, a transfer function from the simulation file for one or more nodes of the simulation file; determining, by the processor, the first value for the first component from the transfer function using a known input/output profile for the analog circuit; executing, by the processor, the simulation file using the determined first value to simulate operation of the analog circuit for determining a simulated output profile; and based at least partially on determining that a difference between the simulated output profile and the known input/output profile is less than a threshold error amount, outputting, by the processor, a result indicating that the created simulation file has passed validation.