Goertzel:

Filter: Extension

Calculate a single DFT bin, to detect presence of a frequency

Source: MCLDFilterUGens.sc

The Goertzel algorithm is a way to calculate the magnitude and phase of a signal's content at a single specified frequency. It's the equivalent of running an FFT, and then only looking at the output corresponding to a single bin. If you're only interested in a small number of bins then it is more efficient; if you're interested in the majority of bins, you typically want to do an FFT instead.

in | |

bufsize |
used in the same way as an FFT buffer size - the larger this value, the better the frequency resolution, but the worse the time resolution. |

freq |
target frequency. This can not be modulated. |

hop |
same meaning as in the FFT UGen. Supply a value between zero and one, for the amount of overlap between Goertzel "frames". The default is a hop of 1 (meaning no overlap between frames). If you specify 0.5 then the analysis value will be produced twice as often; 0.25, four times as often. |

helpfile source: /usr/local/share/SuperCollider/Extensions/SC3plugins/MCLDUGens/HelpSource/Classes/Goertzel.schelp

link::Classes/Goertzel::

link::Classes/Goertzel::