PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

(sharon) #1

348 Practical MATLAB® Applications for Engineers


e. Differentiation in freq(s)

tft
dF s
ds

⋅↔()


()


or a more general relation is given by

() () 1 nn [()]

n
tft n
d
ds

↔ Fs

f. Differentiation in t
df t
dt

sF s f

()


↔ () ( ) 0 


The second derivative is given by

d
dt

df t
dt

d
dt

ft ssFs f f

sFs s

()


[ ( )] [ ( ) ( )] ( )


()










 ↔


2
2

2




00







fff() ()00

The preceding process can be repeated for higher-order derivatives.
g. Integration in s

ft
t

Fsds

()


↔ ()




(^0)
h. Periodic functions f(t), with period T > 0
ft
e ftdt
e
T st
() sT


()


()






 

0

(^1)
i. Integration in t
fd sFs
f
() () s


()




0

1 0


∫ ↔ 


j. Convolution in t or product in s

ft 12 ()⊗↔ft() f 12 ( ) (ft )d [ () ()]FsFs 12


∫





k. Product in t or convolution in s

ftft
j
12 Fs 1 Fs 2

1


2


() ()↔⊗[ () ()]




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