- Frequencies calculated for sampled sine wave
- At 6 cycles per 2π radians, expected result is slightly under 1 cycle per radian
- Over 0 - 2π: 0.9549 cycles per radian
- 0 - 4π: 0.9549
- 0 - 8π: about the same, 24 peaks counted
- 0 - 16π: very low, only 11 peaks
- At 6 cycles per 2π radians, expected result is slightly under 1 cycle per radian
- Theorem says: To accurately recreate wave of frequency f, you
have sample at a rate of least 2f
- Undersampling produces “aliasing,” the appearance of a low frequency where there should be a high one
- Relevant to, e.g., digital music, which is a sampled sound wave
- Or any video, which is a series of still image samples. Aliasing making moving wheels seem to turn backwards is common, e.g., https://www.youtube.com/watch?v=jHS9JGkEOmA
- Plotting in Matlab
- Section 3.5
- “Parametric Curves” video at https://www.youtube.com/watch?v=tsnHL1Lb5MU