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Implements a second order filter that extracts the energy present at a specified frequency.

Use the Goertzel VI instead of the FFT VI if you have only a few frequencies to analyze.

Details  

	Goertzel Input is the signal to analyze.
	frequency of interest is the frequency of the signal in hertz to use to extract the energy.
	sample rate specifies the sampling interval.
	Goertzel output contains the calculated frequency domain magnitude at the frequency you specify in frequency of interest.

Goertzel Details

You can use the Goertzel VI to efficiently perform tone detection. The Goertzel algorithm shown below is computationally more efficient than using a dedicated Fast Fourier Transform.

where

fj is the frequency of interest

fs is the sample rate