FFT (Fast Fourier Transform) algorithm???

Voltage

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  • Feb 6, 2012
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    ඉන්ධන මිල සූතය තේරුම් ගන්නත් ගොඩක් වෙලා ගියා
    ඉතින් FFT එක ගැන කවර කතාද :rolleyes:
     

    KasunKDP

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    ඉන්ධන මිල සූතය තේරුම් ගන්නත් ගොඩක් වෙලා ගියා
    ඉතින් FFT එක ගැන කවර කතාද :rolleyes:

    :sorry: උබ cs/IT ද කරන්නේ ? ඔකේ implementation එකක් දැක්කද ?
     

    KasunKDP

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    What exactly do you need to know?

    ඕකෙන් සරලව මොකක්ද වෙන්නේ ?sound clip එකක් input කරාම එකෙන් frequency graph එකක් ගන්න ඕනේ..c# වලින්, එක කරන්න FTT එක පාවිච්චි කරන්න වෙනවා ලු...

    මම java වලින් implement කරලා තියන එකක බැලුව, අජපල් වගේ... :sorry:

    ඕක ඉගනගන්න පුලුවන් වෙයිද 'දවසකින්'...? maths phsycis collage level දැනුමක් නැති කෙන්ක්ට ?
     

    imhotep

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  • Mar 29, 2017
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    ඕකෙන් සරලව මොකක්ද වෙන්නේ ?sound clip එකක් input කරාම එකෙන් frequency graph එකක් ගන්න ඕනේ..c# වලින්, එක කරන්න FTT එක පාවිච්චි කරන්න වෙනවා ලු...

    මම java වලින් implement කරලා තියන එකක බැලුව, අජපල් වගේ... :sorry:

    ඕක ඉගනගන්න පුලුවන් වෙයිද 'දවසකින්'...? maths phsycis collage level දැනුමක් නැති කෙන්ක්ට ?

    The speed varies on how you implement it. The fastest implementation was FFTW (Fastest Fourier Transform in the west - developed by some staff in MIT). http://www.fftw.org/
    It's a bit old and maybe there are newer ones. These days we use Matlab fft function.
    It's mostly used for any signal processing.. not only sound.
    Read a book on DSP (Digital Signal Processing) to understand how it's used for signal analysis.
    For a brief introduction read...
    https://www.dspguide.com/ch12/2.htm
     
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    KasunKDP

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    The speed varies on how you implement it. The fastest implementation was FFTW (Fastest Fourier Transform in the west - developed by some staff in MIT).
    It's a bit old and maybe there are newer ones. These days we use Matlab fft function.
    It's mostly used for any signal processing.. not only sound.
    Read a book on DSP (Digital Signal Processing) to understand how it's used for signal analysis.
    For a brief introduction read...
    https://www.dspguide.com/ch12/2.htm

    thanks..
    that looks somewhat coherent.
     

    wdsmedia

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  • Feb 14, 2009
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    FFT (Fast Fourier Transform) algorithm එක තේරෙන එකක් ඉන්නවදෝ?


    Okeee wenne mekai machoo......dan api hithamu....mokak hari audio signal ekak thiyanwa kyla.......ethakota...audio signal ekak kiyanee.....mix of number of frequencies neee.....api hithamuu....

    eee signal eke thiyenne....H1 +H2+H3+H5...= H5 ethakota H5 thamai ubata dan thiyana signal eka.......

    dan FFT eken karannee...H5 signal eka analyziz karala.......ubata output ekedi kylawa....H5 hadila thiyenne.....H1..H2..H3...eke sum eken kyla......

    Onna ookai wenne...
     

    KasunKDP

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    long time ago did for a uni project used convolution integral to evaluate fft



    Okeee wenne mekai machoo......dan api hithamu....mokak hari audio signal ekak thiyanwa kyla.......ethakota...audio signal ekak kiyanee.....mix of number of frequencies neee.....api hithamuu....

    eee signal eke thiyenne....H1 +H2+H3+H5...= H5 ethakota H5 thamai ubata dan thiyana signal eka.......

    dan FFT eken karannee...H5 signal eka analyziz karala.......ubata output ekedi kylawa....H5 hadila thiyenne.....H1..H2..H3...eke sum eken kyla......

    Onna ookai wenne...

    thanks machn
     

    imhotep

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    long time ago did for a uni project used convolution integral to evaluate fft

    The convolution theorem is a property of the Fourier transform. Convolution in the time domain equals multiplication in the frequency domain and vice versa.
    Convolution is a powerful technique to calculate the zero state response to an arbitrary input.