# A Few Animations (Using MATLAB):

**vdp3D1.mp4, vdp3D2.mp4, vdp3D.mp4, vdpPwS.mp4:** Behavior of the Van der Pol oscillator. The system is written:

dY/dt = [y_{2} ; μ(1-y_{1}^{2}) y_{2}-y_{1}]

for μ varying from 0 to 2.5. **(1)** [t,(y_{1},y_{2})], **(2)** [y_{1},y_{2}], **(3)** [t,y_{1},y_{2}], **(4)** Spectra.

The last movie above shows the Power Spectrum of the variables: y_{1} and y_{2} for the previous van der Pol oscillator where μ varies from 0 to 2.5. (16')

**vdp3DL.mp4:** Behavior of Van der Pol oscillator:

dY/dt = [y_{2} ; μ(1-y_{1}^{2}) y_{2}-y_{1}]

for μ = -0.8,....,2.4. (22')

**CHsignals.mp4:** Cohen class Time-Frequency Distribution of a signal that consists of (1) two slighly different Gabor atoms whose internal frequencies progressively increase, (2) a Dirac, (3) a sinusoid, (4) a noise that increases at each sequence repetition.(23').