Emmanuel has, you can find it in the zsa.descriptors with loads of other useful externals.

lh

You don't need to program a spectrum analyzer yourself. There's already an object called [spectroscope~], which has a lot of options and is easy to use...or am i missing something?

There are three problems with spectroscope: 1. You cannot link it to a buffer. 2. It doesn't provide alternative scales like mels (much more readable than raw FFT). 3. You cannot even send a message to reset it (so that it starts drawing again at its display's left side).