Fourier transform

[bob]

What would be the easiest way to do a Fourier transform in Java?

Thank you.

 

[glen herrmannsfeldt]

What would be the easiest way to do a Fourier transform in Java?

Easiest is to find an FFT routine written in Java.

Second easiest is to port from a C routine.

Third is to port from Fortran.

-- glen

 

[Frank Langelage]

What would be the easiest way to do a Fourier transform in Java?

Thank you.

May be commons-math including
http://commons.apache.org/math/apid...s/math3/transform/FastFourierTransformer.html
gives you the solution.

 

[Volker Borchert]

Easiest is to find an FFT routine written in Java.

Second easiest is to port from a C routine.

Third is to port from Fortran.

What about using a C/FORTRAN routine/library that exploits the number
crunching power of your high-end graphics processor board via JNI?

 

[Lew]

What would be the easiest way to do a Fourier transform in Java?

What do you call "easy"?

Besides the other excellent suggestions already offered you, there's
<http://en.wikipedia.org/wiki/Fast_Fourier_transform>
from which you can find the algorithms and implement them yourself, if the available library functions don't fulfill your needs.

You can also likely find something useful from
<http://lmgtfy.com/?q=fast+fourier+transform+Java>

which, among many, many good links yielded this gem
https://sites.google.com/site/piotrwendykier/software/jtransforms

Did you try a web search first?

It didn't take me very long to run it for you.

 

[glen herrmannsfeldt]

(snip, then I wrote)

What about using a C/FORTRAN routine/library that exploits the number
crunching power of your high-end graphics processor board via JNI?

I think for me the port would be easier, and also is more portable.
But yes, that is another way to do it.

-- glen

 

[Roedy Green]

What would be the easiest way to do a Fourier transform in Java?

see http://mindprod.com/jgloss/fft.html
--
Roedy Green Canadian Mind Products
http://mindprod.com
It is almost impossible to keep things in synch manually. Instead:
-Keep each fact in only one central database (not necessarily SQL),
and access it as needed. Since there is only one copy of each fact,
there is nothing to get out of synch.
-Use some automated tool so that if you change a fact is one place,
it automatically updates the others.
-Write a sanity checker you run periodically to ensure all is consistent.
This is the strategy compilers use.
-Document the procedures needed to keep all in synch if you change
something and rigidly and mechanically follow them.

 

[Jan Burse]

see http://mindprod.com/jgloss/fft.html

You write in the above:

"Analysing a wave into its equivalent superimposed sine waves of various
frequencies. You can think of it as separating out a tone from its
overtones mathematically. Joseph Fourier (born: 1768-03-21 died:
1830-05-16 at age: 62) was a French mathematician who proved this was
always possible."

It depends on what you understand by a wave. There are the
dirichlet condition, the gibbs phaenomen etc.. which knowingly
invalidated Fouriers initial claim later on.

Bye

 

[Stefan Ram]

dirichlet condition, the gibbs phaenomen

»Gibbs phenomenon«

 

[Jan Burse]

»Gibbs phenomenon«

φαινόμενον

 

[Jan Burse]

»Gibbs phenomenon«

Englisch: phenomenon
Französisch: phénomène
Italienisch: fenomeno
Latein: phaenomenon
Spanisch: fenómeno
Further all lower caps saves
typing energy, so do short words
from foreign languages.

Bye

 

[Jan Burse]

Further all lower caps saves
typing energy, so do short words
from foreign languages.

For example I would write "stefan ram suck
my dick" and not "stefan ram lutsch meinen
schwanz", since the former is shorter than
the later. But I do not follow strickly
all the rules, its more kind of random.

 

[Lew]

Englisch: phenomenon
Französisch: phénomène
Italienisch: fenomeno
Latein: phaenomenon
Spanisch: fenómeno

Further all lower caps saves
typing energy, so do short words
from foreign languages.

How many micro-ergs did you save? Good thing you don't actually have to work
for a living, huh, Jan? You literally don't want to have to lift a finger.
(That's an English idiom.) Wow.

"Phenomenon" is not usually considered a short word in English.

If your purpose is to obscure your message, you've accomplished it.

Since your response to Stefan (not quoted here for politeness' sake) was so
very rude, personal and off color, not to mention completely uncalled-for, I
have to assess that you really are some piece of work, Jan Burse. (That's an
American idiom.) You are both lazy and offensive.

Plonk.

 

[Jan Burse]

"Phenomenon" is not usually considered a short word in English.

My saying, and "phaenomen" is a german word, and its
one letter shorter than the english word.

I guess S.R. was heading to his english library and
guzzling through the physical filing cabinet they
still have there, and did find gibbs phaenomen.

Hint: use google. BTW: My general opinion is that
it doesn't make sense to orthographically correct
any posts on comp.* or somesuch. These posts are
not assumed to go into print.

They are supposed to be an informal exchange
of bits and bytes. Where would it end if you
orthographically correct for example posts from
people who use english more sloppily than I do?

Otherwise I demand a full proof reading by S.R.,
and not only a pick on the text such as:

"Gibbs phenomenon"

The next error is:

"Dirichlet conditions"

i.e. plural and the name upper case.

Bye

 

[Lars Enderin]

2012-03-24 23:24, Jan Burse skrev:

My saying, and "phaenomen" is a german word, and its
one letter shorter than the english word.

I can give you a shorter word: it's "fenomen" in Swedish, and note that
I am not too lazy to hit the shift key when it's called for.

I guess S.R. was heading to his english library and
guzzling through the physical filing cabinet they
still have there, and did find gibbs phaenomen.

Hint: use google. BTW: My general opinion is that
it doesn't make sense to orthographically correct
any posts on comp.* or somesuch. These posts are
not assumed to go into print.

Doesn't matter. Correct ortography is easier to read, and you already
lost several weeks' worth of saved keystrokes by quibbling.

 

[Jan Burse]

I can give you a shorter word: it's "fenomen" in Swedish, and note that
I am not too lazy to hit the shift key when it's called for.

If my mothertongue would be swedish,
I would eventually have used this word.

Since there is no danger in phonetically
misunderstanding it.

I guess there is no english word with
a similar sound that would lead to some
confusion, right?

 

[Jan Burse]

Doesn't matter. Correct ortography is easier to read

I don't dispute this. But if S.R. cannot put
down his teacher attitude maybe a better play-
ground would be alt.usage.english or so.

 

[Arne Vajhøj]

For example I would write "stefan ram suck
my dick" and not "stefan ram lutsch meinen
schwanz", since the former is shorter than
the later. But I do not follow strickly
all the rules, its more kind of random.

Please notify us when you reach the age of 16 ....

Arne

 

[Lars Enderin]

2012-03-24 23:44, Jan Burse skrev:

If my mothertongue would be swedish,
I would eventually have used this word.

You misused "eventually". False friend; look it up. Swedes often get it
wrong, too.

 

[Jan Burse]

Please notify us when you reach the age of 16 ....

Arne

I step back. Googling revealed that S.R. was
already flamed by an expert, Reinhold Aman,
editor of Maledicta. Just try to google the
two names together.

But I didn't find some reactions by S.R.,
so I guess I have no chance in the present
case to excite some response. I was hoping
that he corrects the above to:

"Stefan Ram suck my dick"

Bye