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Fourier transform

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  Fourier transform bob <bob@coolfone.comze.com> - 2012-03-21 07:07 -0700
    Re: Fourier transform Patricia Shanahan <pats@acm.org> - 2012-03-21 07:46 -0700
    Re: Fourier transform glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-21 18:08 +0000
      Re: Fourier transform v_borchert@despammed.com (Volker Borchert) - 2012-03-21 22:59 +0000
        Re: Fourier transform glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-22 03:46 +0000
    Re: Fourier transform Frank Langelage <frank@lafr.de> - 2012-03-21 20:35 +0100
    Re: Fourier transform Lew <lewbloch@gmail.com> - 2012-03-21 18:14 -0700
    Re: Fourier transform Roedy Green <see_website@mindprod.com.invalid> - 2012-03-22 11:28 -0700
      Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 12:34 +0100
        Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 21:40 +0100
        Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 21:52 +0100
          Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 22:17 +0100
            Re: Fourier transform Arne Vajhøj <arne@vajhoej.dk> - 2012-03-24 18:52 -0400
              Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-25 00:34 +0100
          Re: Fourier transform Lew <noone@lewscanon.com> - 2012-03-24 14:55 -0700
            Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 23:24 +0100
              Re: Fourier transform Lars Enderin <lars.enderin@telia.com> - 2012-03-24 23:39 +0100
                Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 23:44 +0100
                  Re: Fourier transform Lars Enderin <lars.enderin@telia.com> - 2012-03-24 23:53 +0100
                    Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-25 00:27 +0100
                Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-24 23:46 +0100
          Re: Fourier transform Roedy Green <see_website@mindprod.com.invalid> - 2012-03-24 19:44 -0700
            Re: Fourier transform Lew <noone@lewscanon.com> - 2012-03-25 14:30 -0700
              Re: Fourier transform Gene Wirchenko <genew@ocis.net> - 2012-03-25 20:42 -0700
                Re: Fourier transform "John B. Matthews" <nospam@nospam.invalid> - 2012-03-26 09:48 -0400
                  Re: Fourier transform Jan Burse <janburse@fastmail.fm> - 2012-03-26 16:06 +0200
            Re: Fourier transform Arne Vajhøj <arne@vajhoej.dk> - 2012-03-25 18:17 -0400

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#13096 — Fourier transform

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

Thank you.

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#13099

bob wrote:
> What would be the easiest way to do a Fourier transform in Java?

How about the Colt library? Does it do what you need?

Patricia

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#13101

bob <bob@coolfone.comze.com> wrote:

> 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

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#13112

glen herrmannsfeldt wrote:
> bob <bob@coolfone.comze.com> wrote:
> 
> > 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.

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

-- 

"I'm a doctor, not a mechanic." Dr Leonard McCoy <mccoy@ncc1701.starfleet.fed>
"I'm a mechanic, not a doctor." Volker Borchert  <v_borchert@despammed.com>

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#13117

Volker Borchert <v_borchert@despammed.com> wrote:

>> bob <bob@coolfone.comze.com> wrote:
>> > What would be the easiest way to do a Fourier transform in Java?

(snip, then I wrote)

>> 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?

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

-- glen

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#13107

On 21.03.12 15:07, bob wrote:
> 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/apidocs/org/apache/commons/math3/transform/FastFourierTransformer.html 
gives you the solution.

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#13116

bob wrote:
> 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.

-- 
Lew


-- 
Lew

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#13124

On Wed, 21 Mar 2012 07:07:05 -0700 (PDT), bob <bob@coolfone.comze.com>
wrote, quoted or indirectly quoted someone who said :

>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.

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#13139

Roedy Green schrieb:
> On Wed, 21 Mar 2012 07:07:05 -0700 (PDT), bob<bob@coolfone.comze.com>
> wrote, quoted or indirectly quoted someone who said :
>
>> What would be the easiest way to do a Fourier transform in Java?
>
> 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

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#13143

Stefan Ram schrieb:
> Jan Burse<janburse@fastmail.fm>  writes:
>> dirichlet condition, the gibbs phaenomen
>
>        »Gibbs phenomenon«
>

φαινόμενον

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#13144

Stefan Ram schrieb:
> Jan Burse<janburse@fastmail.fm>  writes:
>> dirichlet condition, the gibbs phaenomen
>
>        »Gibbs phenomenon«
>

     Englisch: phenomenon
     Französisch: phénomène
     Italienisch: fenomeno
     Latein: phaenomenon
     Spanisch: fenómeno
 >>> Deutsch: Phänomen <<<

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

Bye

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#13145

Jan Burse schrieb:
>
> 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.

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#13152

On 3/24/2012 5:17 PM, Jan Burse wrote:
> Jan Burse schrieb:
>> 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.

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

Arne

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#13155

Arne Vajhøj schrieb:
> On 3/24/2012 5:17 PM, Jan Burse wrote:
>> Jan Burse schrieb:
>>> 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.
>
> 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

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#13147

Jan Burse wrote:
> Stefan Ram schrieb:
>> Jan Burse<janburse@fastmail.fm> writes:
>>> dirichlet condition, the gibbs phaenomen
>>
>> »Gibbs phenomenon«
>>
>
> Englisch: phenomenon
> Französisch: phénomène
> Italienisch: fenomeno
> Latein: phaenomenon
> Spanisch: fenómeno
>  >>> Deutsch: Phänomen <<<
>
> 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.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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#13148

Lew schrieb:
> "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

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#13149

2012-03-24 23:24, Jan Burse skrev:
> Lew schrieb:
>> "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 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.

> 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.
> 


-- 
Lars Enderin

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#13150

Lars Enderin schrieb:
> 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?

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#13153

2012-03-24 23:44, Jan Burse skrev:
> Lars Enderin schrieb:
>> 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.

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

> 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?


-- 
Lars Enderin

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#13154

Lars Enderin schrieb:
> You misused "eventually". False friend; look it up. Swedes often get it
> wrong, too.

Quite possible.

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