This Demonstration also illustrates the use of different algorithms to reconstruct the signal from the signal .
The time domain signal is made of two harmonics. You can vary the amplitude and the frequency of each harmonic as well as the sampling frequency, the duration of , and the delay time. The spectrum of and of are also displayed (the magnitude and the phase spectra). A number of plotting options are available to help analyze the results generated.
The following important relation between the CTFT and the DTFT is observed: The CTFT is an aperiodic and continuous function. The DTFT is also a continuous function, but it is a periodic function with a period of . The maximum frequency present in the DTFT is in radians (or in cycles). In addition, there is a scaling effect: the magnitude spectrum of is of the magnitude spectrum of , where is the sampling period. The units of the DTFT are radians, while the units of the CTFT are in radians per second.