Finally, based on the characteristics of the filter, one chooses a sample-rate ( and corresponding Nyquist frequency ) that will provide an acceptably small amount of aliasing.
22.
Zero frequency ( DC ) corresponds to ( 1, 0 ), positive frequencies advancing counterclockwise around the circle to the Nyquist frequency at (-1, 0 ).
23.
Some programs ( such as MATLAB ) that design filters with real-valued coefficients use the Nyquist frequency ( \ textstyle f _ s / 2 ) as the normalization constant.
24.
The fact that DACs output a sequence of piecewise constant values ( known as zero-order hold in sample data textbooks ) or rectangular pulses causes multiple harmonics above the Nyquist frequency.
25.
When the function domain is distance, as in an image sampling system, the sample rate might be dots per inch and the corresponding Nyquist frequency would be in cycles / inch.
26.
Thus, " Nyquist rate " is a property of a continuous-time signal, whereas " Nyquist frequency " is a property of a discrete-time system.
27.
In terms of actual frequency, the cutoff is \ tfrac { 0.5 } { T } Hz, which is the Nyquist frequency of the original x [ n ] sequence.
28.
If a piece of music is sampled at 32000 Hz ( the Nyquist frequency for this sampling rate ) will cause aliasing when the music is reproduced by a digital to analog converter ( DAC ).
29.
The Nyquist frequency should not be confused with the " Nyquist rate ", which is the minimum sampling rate that satisfies the Nyquist sampling criterion for a given signal or family of signals.
30.
They are offset from the vertical by 5 degrees so that the edges will be sampled in many different phases, which allow estimation of the spatial frequency response beyond the Nyquist frequency of the sampling.
