SIG—A general-purpose signal processing program

SIG is a general-purpose customizable signal processing, analysis, and display program. Its main purpose is to perform manipulations on time- and frequency-domain signals, however it accommodates other representations for data such as transfer function polynomials. Signal processing operations include digital filtering, auto/ cross spectral density, transfer function/impulse response, convolution, forward/inverse Fourier transforms, deconvolution, identification, and simulation with ARMAX models. Graphics operations display signals and spectra with capability for cursor zoom, families of curves, and multiple viewport plots. There are two user interfaces, a menu mode for occasional users, and a command mode for daily users. Capability exists for defining custom menus, new commands, and incorporating user-written software.