I'm reading a Goertzel algorithm paper and an embedded article. I have several questions:
- I don't understand why the the magnitude is calculated as follows:
$$\text{Magnitude} = y^2[n-2] + y^2[n-1] - a * y[n-2]y[n-1]$$ where $a$ is some coefficient. Can someone elaborate on why this is the expression?
Minimum block size If I have a sampling rate of 4000 Hz and target frequency of 50 Hz, what is the minimum block size?
If block size more that magnitude will more accurate right?