Fast Fourier Transform of an arbitrary wave

The user can draw an arbitrary time domain signal on the graphics surface using mouse. On every change in the time domain signal, the program will draw its FFT & the reconstructed signal with certain cutoff frequency. The cutoff is determined by a number in a spin box on the control panel on the left side of the graphics surface. The range is 0 to 315. The cutoff frequency is the value in the spin box divided by 100. For example, if the value in the spin box is 50, the cutoff will be at 50/100 radians. The cutoff will be clamped at frequency of PI radians. At Pi radians cutoff, all the frequencies will be considered for reconstruction of the time domain signal.

Download the Program

In the following screenshots --

White colored signal -- User drawn time domain signal
Yellow colored signal -- FFT of the time domain signal
Blue colored signal -- Reconstructed time domain signal after including all the frequencies below the cutoff

Fig 1.1

Fig 1.2

Fig 1.3

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4

Fig 1.4