Fourier and Laplace
407
−5
0
0.1
0.2
0.3
0.4
0.5
0.6
5
−5
0
0
0.2
0.4
5
−10
−100
−50
50
100
−5
frequency s
Magnitude of F(w)
Magnitude of F(s)
Magnitude spectrum/Fourier
Magnitude spectrum/Laplace
Phase spectrum/Fourier
Phase spectrum /Laplace
0
5
1 0
−5
0
5
10
0
−10
−100
−50
50
100
0
Angle in degrees
Angle in degrees
frequency w
frequency w
frequency s
FIGURE 4.53
Numerical plots of F(w) and F(s) of part 7 of Example 4.9.
FIGURE 4.54
Symbolic plots of F(w) and F(s) of part 7 of Example 4.9.
0.5
0.4
0.3
0.2
−6
−4
−4
−3.5
−3
−2.5
−2
−1.5
−1
−0.5
−2
0
2
4
6
0
40
30
20
10
0
Magnitude of F(s)
Magnitude of F(w)
sym Fourier transf of (exp(-2*t)*u(t))
sym Laplace transf of (exp(-2*t)*u(t))
frequency s
frequency w
CRC_47760_CH004.indd 407
CRC_47760_CH004.indd 407
7/28/2008 12:26:13 PM
7/28/2008 12:26:13 PM