Fourier Transform (inttrans Package)
restart
with⁡inttrans:
assume⁡0<λ,0<a
Introduction
The fourier, fouriersin,and fouriercos transforms are exceptionally interesting and useful examples of integral transforms. The fourier transform itself has many beautiful properties that make it useful in engineering sciences. The fouriersin and fouriercos transforms have uses in spectral analysis of real sequences, in solving some boundary value problems, and in transforming domain processing of digital signals. The inverse fourier transform is simply a front end for fourier.
The definitions of the transforms:
convert⁡fourier⁡f⁡t,t,s,int
∫−∞∞f⁡t⁢ⅇ−I⁢t⁢sⅆt
convert⁡invfourier⁡f⁡t,t,s,int
12⁢∫−∞∞f⁡t⁢ⅇI⁢t⁢sⅆtπ
convert⁡fouriercos⁡f⁡t,t,s,int
2⁢∫0∞f⁡t⁢cos⁡t⁢sⅆtπ
convert⁡fouriersin⁡f⁡t,t,s,int
2⁢∫0∞f⁡t⁢sin⁡t⁢sⅆtπ
Algebraic, Exponential, Logarithmic, Trigonometric, Inverse Trigonometric, and Hyperbolic Functions
f:=randpoly⁡t+a,t,terms=3
f:=87⁢t2−56⁢t+a~2⁢t2
fourier⁡f,t,p
2⁢π⁢−56⁢Dirac⁡4,p+112⁢I⁢a~⁢Dirac⁡3,p−87⁢Dirac⁡2,p+56⁢Dirac⁡2,p⁢a~2
invfourier⁡,p,t
−t2⁢−87+56⁢t2+112⁢t⁢a~+56⁢a~2
fouriercos⁡f,t,p
−872⁢2⁢π+28⁢2⁢a~2⁢π⁢Dirac⁡2,p−28⁢2⁢π⁢Dirac⁡4,p−672⁢a~⁢2π⁢p4
fouriercos⁡,p,t
872⁢t2−28⁢t2⁢a~2−28⁢t4−112⁢t3⁢a~
fouriersin⁡f,t,p
−56⁢2⁢π⁢a~⁢Dirac⁡3,p−174⁢2π⁢p3−56⁢2⁢−2⁢a~2⁢p2+24π⁢p5
fouriersin⁡,p,t
−56⁢t3⁢a~+87⁢t2−56⁢t2⁢a~2−56⁢t4
fourier⁡ⅇ−λ⁢x⁢sech⁡a⁢ⅇ−x,x,y
a~−λ~−I⁢y⁢21−2⁢λ~−2⁢I⁢y⁢Γ⁡λ~+I⁢y⁢ζ⁡0,λ~+I⁢y,14−ζ⁡0,λ~+I⁢y,34
fouriercos⁡ⅇ−a⁢x,x,y
2⁢a~π⁢a~2+y2
fouriersin⁡ⅇ−a⁢x,x,y
2⁢yπ⁢a~2+y2
fourier⁡ln⁡11+x2,x,y
π⁢−ⅇy⁢Heaviside⁡−y+ⅇ−y⁢Heaviside⁡yy
fouriercos⁡1⁢ln⁡a+xa−xx,x,y
−2⁢π⁢Ssi⁡a~⁢y
fouriersin⁡ⅇ−x⁢ln⁡x,x,y
2⁢arctan⁡y−γ⁢y−12⁢y⁢ln⁡y2+1π⁢y2+1
fourier⁡sin⁡a⁢x,x,y
I⁢π⁢−Dirac⁡y−a~+Dirac⁡y+a~
fouriercos⁡cos⁡x2x,x,y
∫y∞2⁢sin⁡14⁢_U2⁢FresnelC⁡18⁢2⁢π⁢_U2−cos⁡14⁢_U2⁢FresnelS⁡18⁢2⁢π⁢_U2πⅆ_U
fouriersin⁡cos⁡x2x,x,y
12⁢2⁢π⁢2⁢FresnelC⁡18⁢y2⁢2⁢ππ+2⁢FresnelS⁡18⁢y2⁢2⁢ππ
fouriercos⁡arccos⁡x⁢Heaviside⁡1−x,x,y
12⁢2⁢π⁢StruveH⁡0,yy
fouriersin⁡arcsin⁡x⁢Heaviside⁡1−x,x,y
12⁢2⁢π⁢BesselJ⁡0,y−cos⁡yy
fouriercos⁡tanh⁡a⁢xx,x,y
12⁢2⁢ln⁡cosh⁡12⁢y⁢πa~+1cosh⁡12⁢y⁢πa~−1π
fouriersin⁡tanh⁡a⁢xx,x,y
2⁢12⁢π−I⁢lnGAMMA⁡12+14⁢I⁢ya~−I⁢lnGAMMA⁡1−14⁢I⁢ya~+I⁢lnGAMMA⁡12−14⁢I⁢ya~+I⁢lnGAMMA⁡1+14⁢I⁢ya~π
Fresnel's Sine and Cosine Integrals
fouriercos⁡FresnelC⁡1x,x,y
14⁢sin⁡2⁢2⁢yπ+cos⁡2⁢2⁢yπ−ⅇ−2⁢2⁢yπy
fouriersin⁡FresnelS⁡ax,x,y
14⁢2−ⅇ−2⁢a~⁢2⁢yπ−cos⁡2⁢a~⁢2⁢yπ−sin⁡2⁢a~⁢2⁢yπy
Exponential, Sine, and Cosine Integrals
fouriercos⁡Ei⁡a⁢x,x,y
2⁢arctan⁡ya~π⁢y
fouriersin⁡Ssi⁡−a⁢x,x,y
12⁢2⁢π⁢Heaviside⁡y−a~y−2⁢πy
The Error Function
fouriercos⁡erf⁡x⁢ax,x,y
−12⁢2⁢Ei⁡−14⁢y2a~2π
fouriersin⁡erf⁡x,x,y
2⁢1y−1−ⅇ−14⁢y2yπ
Bessel and Modified Bessel Functions
fourier⁡BesselJ⁡0,x,x,y
2⁢Heaviside⁡1+y−Heaviside⁡y−11−y2
fouriercos⁡BesselY⁡0,a⁢x2,x,y
−18⁢2⁢π⁢y⁢BesselJ⁡14,18⁢y2a~2+BesselJ⁡−14,18⁢y2a~2a~
fouriersin⁡BesselK⁡0,a⁢x,x,y
2⁢ln⁡ya~+1+y2a~2π⁢a~2−y2
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