Anyone know about Fourier Transforms?

[PurdueRy]

If you have a good about of knowledge about these, PM me, I need a little help with a few.

 

[Stojakapimp]

depends how complicated they are. You need help with integrals and such, or just basic concepts of it?

 

[Ready]

I wasn't aware that there was a Transformer name Fourier, but I bet he's very perioidic

 

[PurdueRy]

Let me give an example

I know that the inverse fourier transform of 1/(jw+5) is e^-5t

but how would I do 1/(jw+5)^2?

 

[LordMorpheus]

I can help, maybe. I'm a Mechanical engineer, but I'm taking some elec classes, one of which involved FT's. I've got a good grasp of them, but it is possible whatever you have is beyond me.

 

[Rastus]

Prime95's Lucas-Lehmer tests are FFT's. Go to this forum and ask. It might take a while to get an answer, but there are a lot of specialists there.

 

[PurdueRy]

Originally posted by: LordMorpheus
I can help, maybe. I'm a Mechanical engineer, but I'm taking some elec classes, one of which involved FT's. I've got a good grasp of them, but it is possible whatever you have is beyond me.

Have any idea on how to go about the one I posted?

 

[Brackis]

Fast Fourier Transform? It rings a bell, I will await real knowledge.

 

[hypn0tik]

Originally posted by: PurdueRy

Originally posted by: LordMorpheus
I can help, maybe. I'm a Mechanical engineer, but I'm taking some elec classes, one of which involved FT's. I've got a good grasp of them, but it is possible whatever you have is beyond me.

Have any idea on how to go about the one I posted?

Yeah, consider differentiation in w.

 

[Ready]

Originally posted by: PurdueRy
Let me give an example

I know that the inverse fourier transform of 1/(jw+5) is e^-5t

but how would I do 1/(jw+5)^2?

Have you tried reading the book?

 

[Stojakapimp]

damn....there are rules for when you square something like that, but I don't have my EE books with me. They are at work. But you should have a table of properties somewhere for FFTs. It will tell you what to do to the inverse transform

 

[PurdueRy]

Originally posted by: Stojakapimp
damn....there are rules for when you square something like that, but I don't have my EE books with me. They are at work. But you should have a table of properties somewhere for FFTs. It will tell you what to do to the inverse transform

I've been looking, maybe I will find it.

EDITED because i am just frustrated

 

[Ready]

Originally posted by: Stojakapimp
damn....there are rules for when you square something like that, but I don't have my EE books with me. They are at work. But you should have a table of properties somewhere for FFTs. It will tell you what to do to the inverse transform

yes, that table of property is in every network analysis book

 

[Ready]

Originally posted by: PurdueRy

Originally posted by: Stojakapimp
damn....there are rules for when you square something like that, but I don't have my EE books with me. They are at work. But you should have a table of properties somewhere for FFTs. It will tell you what to do to the inverse transform

I've been looking, maybe I will find it.

And shutup Ready

I guess that says alot about Prudue engineering

 

[hypn0tik]

PurdueRy, what book are you using?

 

[PurdueRy]

Originally posted by: Ready

Originally posted by: PurdueRy

Originally posted by: Stojakapimp
damn....there are rules for when you square something like that, but I don't have my EE books with me. They are at work. But you should have a table of properties somewhere for FFTs. It will tell you what to do to the inverse transform

I've been looking, maybe I will find it.

And shutup Ready

I guess that says alot about Prudue engineering

edited for frustration

 

[PurdueRy]

Originally posted by: hypn0tik
PurdueRy, what book are you using?

Oppenheim's Signals and systems

 

[hypn0tik]

Originally posted by: PurdueRy

Originally posted by: hypn0tik
PurdueRy, what book are you using?

Oppenheim's Signals and systems

Money.

Take a look at page 321, right before example 4.20

Edit: Assuming of course you have the 2nd edition.

 

[PurdueRy]

Originally posted by: hypn0tik

Originally posted by: PurdueRy

Originally posted by: hypn0tik
PurdueRy, what book are you using?

Oppenheim's Signals and systems

Money.

Take a look at page 321, right before example 4.20

Edit: Assuming of course you have the 2nd edition.

Saweeet, thats perfect! Thank you all

 

[hypn0tik]

Make sure you understand how they got that result. Or I guess you could just memorize it, lol.

Good luck.

Anything else, just ask.

 

[PurdueRy]

Originally posted by: hypn0tik
Make sure you understand how they got that result. Or I guess you could just memorize it, lol.

Good luck.

Anything else, just ask.

oh trust me, I know I need to understand it.

While I have someone here with experience, got any clues about:

((jw+2)(jw+5))/(jw-1)

 

[Chaotic42]

Originally posted by: Ready
I guess that says alot about Prudue engineering

Purdue is an excellent school. I always hope they lose in basketball, but they're a very good engineering school.

 

[RaynorWolfcastle]

I'm pretty sure this is an identity that you can get from the integral relation in a pretty straight forward fashion. From memory it'll have a form like f(t)=t*exp(-a*t); give me a second to remember how to do this

 

[hypn0tik]

Originally posted by: RaynorWolfcastle
I'm pretty sure this is an identity that you can get from the integral relation in a pretty straight forward fashion. From memory it'll have a form like f(t)=t*exp(-a*t); give me a second to remember how to do this

You differentiate the analysis equation with respect to w to get that result.

 

[hypn0tik]

Originally posted by: PurdueRy

Originally posted by: hypn0tik
Make sure you understand how they got that result. Or I guess you could just memorize it, lol.

Good luck.

Anything else, just ask.

oh trust me, I know I need to understand it.

While I have someone here with experience, got any clues about:

((jw+2)(jw+5))/(jw-1)

Not sure about that one. Let me try it out.