3 ms·

As a controls engineer, I strongly discourage using hertz as a measure of events. It's an abuse of notation. In control theory and signal processing, we refer

As a controls engineer, I strongly discourage using hertz as a measure of events. It's an abuse of notation. In control theory and signal processing, we refer to the frequencies that make up a signal in hertz. The maximum frequency a control law can track is called its bandwidth, which is in hertz. Frequencies a filter is passing or stopping are in hertz. Computers being digital, we have to run that control law or signal processing algorithm at some rate. That rate also gets referred to in hertz, a lot, and it is a cause of no end of confusion, because the running rate of the algorithm is very much not the same as the bandwidth or filter bandpass. The Nyquist criterion says that the algorithm has to run at least twice as fast as the frequency of interest, but practice more like ten times faster. SO when we refer to a control law as "500 Hz" or whatever, I have to explain which sense I mean every damn time. Don't do it. Events happen at events per second. Hertz refers to sine waves, and NOTHING ELSE.

xxs 3y ago
Given that any waveform can be produced out of "sine waves", we can call those events call composite sine, falling back to Hertz. The said request most likely have originated as some sines as well, think of your phone for instance. Seriously, though, using Hertz would be confusing to a high degree.
- TylerE 3y ago
  The sine wave thing is technically true, but if you try it in practice, as I did extensively in a college acoustics course, you’ll find that making even a decent approximation of a square or a saw wave requires sine waves at many multiples of the upper threshold of human hearing. You need those insanely high overtones to produce sharp “corners” in the wave form.
  - xxs 3y ago
    Of course, making square wave oscillators is very difficult at any frequency - there is always some rounding around the 'corners'

xxs 3y ago

Given that any waveform can be produced out of "sine waves", we can call those events call composite sine, falling back to Hertz. The said request most likely have originated as some sines as well, think of your phone for instance. Seriously, though, using Hertz would be confusing to a high degree.

TylerE 3y ago
The sine wave thing is technically true, but if you try it in practice, as I did extensively in a college acoustics course, you’ll find that making even a decent approximation of a square or a saw wave requires sine waves at many multiples of the upper threshold of human hearing. You need those insanely high overtones to produce sharp “corners” in the wave form.
- xxs 3y ago
  Of course, making square wave oscillators is very difficult at any frequency - there is always some rounding around the 'corners'