Audacity Forum

The value 1020 is nowhere mentioned but you can take for granted that it is true. I've stumbled over it only per Chance. If it is useful for your Analysis to take odd numbers, do so. For example: to inspect a Signal for 60 Hz hum, it is ideally to take an window size of 735 (at 44.1 kHz) because eac...

Frame size and window size are identical. 32 samples return 32 coefficients. The frequencies are samplerate/window size Hz apart (from DC to Nyquist). But as you've mentioned earlier, snd-fft grabs always chunks of 1020 samples (equal to the destructive effect of snd-fetch). Or are you refferring to...

I can't follow you. The calculated value from the mentioned code (only from one Frame), which you describe as RMS is just the Amplitude for any given frequency, and this is of course directly comparable with a scaler. It is only written in linear form, i.e. 0.5 = -6 dB. Maybe this will help you more...

The FFT-mod (FM) example has somewhat hidden the code to calculate from real cosine/sine to amplitude (/phase).

That's about right.
To me, objects of this Kind are bad because they do not allow random Access (compare the Show coeffs functions). The objects have always to be gone thru from start to end, no matter which Frame you want to inspect.

"Neither of the above is right" or all...
You've mixed up two different functions:
- (sref-inverse)
- (snd-inverse)
The former searches for the first appearance of a value and Returns the time index.
The latter constructs lookup-tables.
snd-inverse is not used by the Zero crossing detection.

The init.lsp file is recommended for this Task:

The Zero variable is not used because the function is only an extract from a greater script. It is initially used to extent s by a Zero sample. This is necessary because integrate doesn't otherwise return the last running sum for the Signal it is fed with. The internal integrate function has some pe...

Those keys are assigned to Keep the dialogs accessible.
And the tab key is the most important of them all, without it, we couldn't find our way through the different fields.

Sorry, I Forget sometimes that not all users are familiar with the Nyquist prompt. It is a simple Interpreter for the LISP Derivate language Nyquist. It is fairly easy and can handle almost every Audio Problem, although it is rather intended for Sound Synthesis. The prompt is the test Portal for cod...