Determine all possible difference and combinations tones from a set of frequencies, and find the closest one to a specified frequency
tones(a=NULL,freqs=NULL,f=T)
The frequency you are seeking to match, in cycles/ka.
The vector of frequencies from which to calculate difference and combination tones, in cycles/ka.
Output results as frequencies (cycles/ka)? If false, will output results as periods (ka). (T or F)