thumb|Fig 1: Typical example of Nyquist frequency and rate. They are rarely equal, because that would require over-sampling by a factor of 2 (i.e. 4 times the bandwidth).
In signal processing, the Nyquist rate is a value equal to twice the highest frequency (bandwidth) of a given function or signal. It is named after Harry Nyquist. It has units of samples per unit time, conventionally expressed as samples per second, or hertz (Hz).
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