Fourier Analysis

$\frac{{\partial}^2 \mu}{ \partial t^2 }=c^2 {\nabla}^2 \mu$

• fourier series(Quadrant II) -> fourier transfom(Quadrant III): The period is infinite, so frequency domain becomes continuous.
• fourier series(Quadrant II)-> discrete time fourier transform(Quadrant IV)
• Time domain and frequency domain is symmetric.
• Frequency domain becomes period if time domain is discrete.
• The period is infinite, so frequency domain becomes continuous.
• discrete time fourier transform(Quadrant IV) -> discrete fourier transform(Quadrant I): Frequency domain becomes discrete if time domain is periodic
page revision: 195, last edited: 03 May 2017 01:35