Laplace•ÏŠ·EFourier‹‰”“W ŠJ‚ÅŽg‚í‚ê‚éŠÖ”‚̃Oƒ‰ƒt

’˜ŽÒFmathcot

‰”ÅF2007.07.05
Update:2012.03.23

’PˆÊŠK’iŠÖ”(Unit Step Function) u(t)

u(t)=0 (tƒ0)
    =1 (t†0)
ut-01.PNG
(Lapalace•ÏŠ·)
[Mathmatica]
Heavicide(t)


[wxMaxima]
unit_step(t)
ut-03.PNG
[wxMaxima]
plot2d(unit_step(x),[x,-1,2],[y,-.5,1.5]);
unit_step(0);
0
limit(unit_step(t),t,0,plus);
1
u(t)=0 (tƒ0)
    =1/2 (t=0)
    = 1 (t„0)
ut-02.PNG
(Fourier‹‰”“WŠJ)
[Maple10]
Heavicide(t)
csgn(t)=0 (t=0)
        =1 (t„0)
        =-1 (tƒ0)
[Maple10]

unit_step(t)=0(x…0)
               =1(x„0)
(Laplace•ÏŠ·)
[Maxima]
load(orthopoly);
unit_step(t)
laplace(unit_step(t),t,s)
signum(t)=0 (t=0)
        =1 (t„0)
        =-1 (tƒ0)
[Maxima]
load(orthopoly);
signum(t)
(1+signum(t))/2=0 (tƒ0)
    =1/2 (t=0)
    = 1 (t„0)
(Fourier‹‰”“WŠJ)
[Maxima]
load(orthopoly);
(1+signum(t))/2

ƒpƒ‹ƒX”gŒ`
Unit StepŠÖ”

y=u (t) ‚Ì
ƒvƒƒbƒg

[Maple10]Žg—p
csgn(t)=1 (t>0)
         =0 (t=0)
         =-1(t<0)
US-00.PNG
’x‰„Unit StepŠÖ”

y=u (t-1) ‚Ì
ƒvƒƒbƒg

[Maple10]Žg—p
csgn(t)=1 (t>1)
         =0 (t=1)
         =-1(t<1)
US-01.PNG
‹éŒ`”g
ŽüŠúT=4
U•=}1

f (t)=-1(-2…tƒ-1)
     =  1(-1…t… 1)
     =-1(  1…tƒ 2)

[Maple10]Žg—p
csgn(t)=1 (t>0)
         =0 (t=0)
         =-1(t<0)
US-02.PNG
‘S”g®—¬sin”g
ŽüŠúT=1,U•=1

y = sin(ƒÎt)  ( 0…tƒ0.5)
  = -sin(ƒÎt) (-0.5…tƒ0)

[Maple10]Žg—p
csgn(t)=1 (t>0)
         =0 (t=0)
         =-1(t<0)
US-04.PNG
‘S”g®—¬cos”g
ŽüŠúT=1,U•=1

y = cos(ƒÎt)  ( 0…|t|ƒ0.5)
  = -cos(ƒÎt) (-0.5…|t| )

[Maple10]Žg—p
csgn(t)=1 (t>0)
         =0 (t=0)
         =-1(t<0)
US-05.PNG
 
ƒÂŠÖ”(delta function) ƒÂ(t)

ƒÂ(t)=0 (tƒ0, t„0)
      =‡ (t=0)
ç[-‡¨‡] ƒÂ(t)dt=1
ç[-‡¨‡] ‚†(t)ƒÂ(t-a)dt=f(a)
[Mathematica]
Dirac(t)
[Maple10]
Dirac(t)




Copyright(C) 2007-2012 Mathcot.H.I  All rights reserved.
XV—š—ð
‰”ÅF2007.07.05
Update:2008.01.14
Update:2008.10.04
Update:2012.03.23



inserted
      by FC2 system inserted by FC2 system