Top: The red line shows the sampled sine wave. The green dots are the sampled points.

Bottom: This shows the frequency spectrum (in blue or blinking blue/red) obtained from the samples. The green bars show the sampling rate and its harmonics (i.e. fs, 2*fs, 3*fs...).

Getting started

Starting with the default settings, move the "mode" slider to various values. Note that the sample points don't change even though the waveform being sampled has changed.

Now try changing the Frequency and Sample rate sliders and observe how the sample points and spectrum change in response.