Question about roots of unity in the Fast Fourier Transform The Next CEO of Stack...

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Question about roots of unity in the Fast Fourier Transform



The Next CEO of Stack OverflowNumerical Approximation of the Continuous Fourier TransformUsing the Discrete and Fast Fourier Transform for Polynomial MultiplicationConcrete FFT polynomial multiplication exampleWhat is the sum of ALL of the nth powers of the qth roots of unity?Calculating of roots of unityWhich are the wavenumbers for the fast Fast Fourier Transform?Derivatives using fft in MatlabComputing remainders modulo $prod_{iin S} (x-x_i)$ fast using FFTDiscrete versions of the Fourier Slice-Projection TheoremBest Approximation Theorem - Fourier Series












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I am learning about the Fast Fourier Transform, which converts a polynomial from its coefficient representation into its point-wise form using divide-and-conquer. The Fast Fourier Transform evaluates a polynomial of degree 'n' at 'n' distinct points. The 'n' distinct points are the 'nth' roots of unity.



I know that a root of unity is a complex number that when raised to some positive integer power 'n' is equal to 1. However, I am not sure what is the advantage of using roots of unity in the Fast Fourier Transform. Any insights are appreciated.










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    1












    $begingroup$


    I am learning about the Fast Fourier Transform, which converts a polynomial from its coefficient representation into its point-wise form using divide-and-conquer. The Fast Fourier Transform evaluates a polynomial of degree 'n' at 'n' distinct points. The 'n' distinct points are the 'nth' roots of unity.



    I know that a root of unity is a complex number that when raised to some positive integer power 'n' is equal to 1. However, I am not sure what is the advantage of using roots of unity in the Fast Fourier Transform. Any insights are appreciated.










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      I am learning about the Fast Fourier Transform, which converts a polynomial from its coefficient representation into its point-wise form using divide-and-conquer. The Fast Fourier Transform evaluates a polynomial of degree 'n' at 'n' distinct points. The 'n' distinct points are the 'nth' roots of unity.



      I know that a root of unity is a complex number that when raised to some positive integer power 'n' is equal to 1. However, I am not sure what is the advantage of using roots of unity in the Fast Fourier Transform. Any insights are appreciated.










      share|cite|improve this question









      $endgroup$




      I am learning about the Fast Fourier Transform, which converts a polynomial from its coefficient representation into its point-wise form using divide-and-conquer. The Fast Fourier Transform evaluates a polynomial of degree 'n' at 'n' distinct points. The 'n' distinct points are the 'nth' roots of unity.



      I know that a root of unity is a complex number that when raised to some positive integer power 'n' is equal to 1. However, I am not sure what is the advantage of using roots of unity in the Fast Fourier Transform. Any insights are appreciated.







      fourier-analysis roots-of-unity fast-fourier-transform






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      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Mar 17 at 7:19









      ceno980ceno980

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