Controls
  1. Plot Box: Input
  2. Plot Box: x[n]
  3. Plot Box: Output
  4. Plot Box: Continuous Time Spectrum
  5. Plot Box: Discrete Time Spectrum
  6. Rad/sec
  7. Radian
  8. f0/w0
  9. fs/ws
  10. Phase
Plot Box: Input

This plot displays the Input sinusoidal signal, whose frequency f0 and phase terms are specified at the bottom-left of the GUI.

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Plot Box: x[n]

This plot displays the Discrete (sampled) version x[n] of the input signal. The continuous time signal is also overlaid on the discrete samples. If aliasing has occurred, then the overlaid continuous time plot can be toggled between the aliased and unalised signal, by double clicking on this plot.

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Plot Box: Output

This plot shows the continuous time Output, reconstructed from the Discrete signal. If no aliasing has occurred, then the original Input signal is restored.

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Plot Box: Continuous Time Spectrum

This plot shows the Input signal's frequency spectrum. The frequency axis of the plot will either be in Hz or rad/s depending on the 'Rad/sec' setting. A 'yellow' band indicates the frequency range -fs/ 2 to fs/ 2. The input signal frequency is indicated by 'blue' impulse (stem) plots.

This also provides an option to change the frequency of the Input signal. 'Click and drag' the 'blue' stem plot, to change the Input signal frequency.

A similar spectrum for the Output signal is also shown at the bottom-right corner of the GUI. If the output signal has been aliased, then, a text 'ALIASING!' is displayed in this plot.

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Plot Box: Discrete Time Spectrum

This plot shows the spectrum of the discrete (sampled) input signal. The frequency axis of the plot will either be in normalized cyclic or radian frequency depending on the 'Radian' setting. This spectrum also has a yellow band indicating the range -fs/ 2 to fs/ 2. The input signal's frequency is indicated using 'blue' impulse (stem) plots and the aliases of the input frequency are indicated using 'red' impulse plots.

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Rad/sec

This radio-button can be used to set the units to Rad/sec or Hz, for setting the input and sampling frequency. Turning this 'On' also toggles the x-axis label in the continuous time spectrum, between rad/s and Hz.

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Radian

This radio-button can be used to label the frequency axis in the Discrete Time Spectrum plot, either in normalized cyclic frequency(f) or normalized radian frequency(w).

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f0/w0

This slider/edit-box can be used to set the frequency of input signal. The frequency can be specified in either Hz or rad/s depending on Rad/sec setting. The maximum value can be 1.5 times the sampling frequency.

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fs/ws

This slider/edit-box can be used to set the sampling frequency, either in Hz or rad/s depending on Rad/sec setting. The maximum value that can be specified is 30Hz or 188rad/s

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Phase

This edit-box can be used to set the phase (in Radians) of the input signal.

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