A BASIC program for the removal of noise from reaction traces using Fourier filtering

Software for the removal of noise from reaction curves usingthe principle of Fourier filtering has been written in BASICto execute on a PC. The program inputs reaction traces whichare subjected to a rotation -inversion process, to produce functionssuitable for Fourier analysis. Fourier transformation into thefrequency domain is followed by multiplication of the transformby a rectangular filter function, to remove the noise frequencies.Inverse transformation then yields a noise-reduced reactiontrace suitable for further analysis. The program is interactiveat each stage and could easily be modified to remove noise froma range of input data types. Received on October 20, 1988; accepted on January 10, 1989