Windowed Fourier Transform of Signals

Write MATLAB code to implement the windowed Fourier transform of signals and generate corresponding graphical results. The specific implementation steps are as follows:

1. First, import the required signal data using functions like load or audioread for audio signals.

2. Then, select an appropriate window function such as rectangular window (rectwin), Hann window (hann), or Hamming window (hamming), each offering different trade-offs between main lobe width and side lobe attenuation.

3. Apply windowing to the signal using element-wise multiplication (.*) to reduce spectral leakage effects caused by finite observation intervals.

4. Perform Fourier transform using fft function to convert the signal from time domain to frequency domain, with optional zero-padding for better frequency resolution.

5. Plot the Fourier transform results using plot or stem functions to display the signal's frequency components, typically showing magnitude spectrum with proper frequency axis scaling.

Through these steps, you can implement windowed Fourier transform in MATLAB and obtain corresponding graphical results that reveal the signal's spectral characteristics with reduced spectral leakage artifacts.