Time-Frequency Wigner Distribution Approach to Differential Equations - Nonlinear Signal and Image Processing: Theory, Methods and Applications - page 128

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

20 40 60 80 100 120 140 160 180 200 220

n

FIGURE 4.6
Approximation of the Wigner distribution W x,x ( t, ω) of the solution x ( t ) of the harmonic oscillator

Ae j β t 2

t 3 / 2 + j γ / 3 . The parameters are

when the forcing function is f ( t ) = β = 1 . 2 π , γ = 1 . 5.

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

20 40 60 80 100 120 140 160 180 200 220

n

FIGURE 4.7
Numerical evaluation of the Wigner W x,x ( t, ω) .