An extensible digital-signal-processing interpreter for use with computer-assisted instrumentation

The authors describe iRALPH, an interpreter for stack-oriented DSP (digital signal processing) programs that provides both a batch-processing language and a command-driven user interface. Using either of these two modes, the user can read and write data files, generate sample data, perform arithmetic functions on the data, generate digital filters, filter the sampled data, and create presentation-quality plots of the results of the analysis. Other operations that can be performed on data include finding the discrete Fourier transform, estimating the power spectral density, and the correlation, and obtaining the histogram. To minimize its complexity, the interpreter was written using yacc and lex, and the primitives have been carefully structured to allow extensions. The extensions can be made by writing procedures in the interpreted language or by writing primitives in the C programming language