Abstract
When an analog operator who has been solving problems on a linearized basis begins to employ nonlinear components to represent a wide range of operation of the simulated system, it soon becomes apparent that many of the key relations in the system are nonlinear functions of two or more input variables. Function-generating equipment that will develop nonlinear functions of a single input variable is now available for many types of analog equipment, but equipment that will generate directly three-dimensional families of curves as arbitrary nonlinear functions of two input variables exists only in a few cases of highly expensive specialized equipment. Some methods also have been described for developing three-dimensional curves by reworking standard function-generating equipment to perform the additional mathematical operations required by a second input variable. This paper describes a graphical method of matching three-dimensional functions by the use of standard analog components without modifications.
