Rank: 1417 based on 98 downloads (last 30 days) and 6 files submitted
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Gylson Thomas

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MES College of Engineering, Kuttippuram,Kerala, India

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14 Nov 2007 Fast 2D Walsh-Hadamard Transform The function implement the 2D dyadic(Paley) ordered fast in-place Walsh-Hadamard transform. Author: Gylson Thomas transforms, walsh transform2d, dyadic, paley, signal processing, pat 18 1
  • 4.0
4.0 | 1 rating
14 Nov 2007 Fast Walsh-Hadamard Transform The function implement the sequency(Walsh) ordered fast Walsh-Hadamard transform. Author: Gylson Thomas transforms, walsh transform, fast, hadamard, 1d, sequency 45 8
  • 4.33333
4.3 | 12 ratings
05 Dec 2006 Radix2 decimation in time 1D fast Fourier transform FFT The function implement the 1D radix2 decimation in time fast Fourier transform FFT algorithm Author: Gylson Thomas spectral analysis, fast fourier transfor... 13 2
  • 4.0
4.0 | 1 rating
05 Dec 2006 natural (Hadamard) and dyadic (Paley) ordered fast Hadamard transform The function implement the 1D natural(Hadamard) and dyadic (Paley) ordered fast Hadamard transform. Author: Gylson Thomas transforms, fast hadamard transfo..., 1d, haramard, dyadic, paley 9 1
  • 5.0
5.0 | 1 rating
17 Mar 2005 Dyadic (Paley) Ordered Hadamard Matrix The function generates the dyadic (Paley) ordered Hadamard matrix. Author: Gylson Thomas application, hadamard matrix, dyadic, paley, image processing, sig 8 0
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19 Nov 2011 Radix2 decimation in time 1D fast Fourier transform FFT The function implement the 1D radix2 decimation in time fast Fourier transform FFT algorithm Author: Gylson Thomas Alex

Or you can have a equation for W like:
W=exp(-i*2*pi*(k-1)/N);

norm(fftf(x)-fft(x)) works fine for me.

05 Apr 2011 Fast 2D Walsh-Hadamard Transform The function implement the 2D dyadic(Paley) ordered fast in-place Walsh-Hadamard transform. Author: Gylson Thomas victorp

Hi Gylson,

I'm trying to use your implementation to convert a gray-scale image (e.g., Lena). Unfortunately, i receive as output a matrix with ALL elements zero!
Could you clarify this?
Regards,
Victor

11 Aug 2009 Fast Walsh-Hadamard Transform The function implement the sequency(Walsh) ordered fast Walsh-Hadamard transform. Author: Gylson Thomas Stephen Becker

As of R2008b, Matlab's Signal Processing toolbox has the functions "fwht" and "ifwht" for the Fast Walsh-Hadamard (aka Hadamard) Transform, and you can choose among three different orderings. This builtin code doesn't work on very large vectors though, whereas I know it is possible to operate on these large vectors because a friend gave me some mex code that does just that. I haven't compared with the file posted here.

27 Aug 2008 Fast Walsh-Hadamard Transform The function implement the sequency(Walsh) ordered fast Walsh-Hadamard transform. Author: Gylson Thomas

26 Aug 2008 Radix2 decimation in time 1D fast Fourier transform FFT The function implement the 1D radix2 decimation in time fast Fourier transform FFT algorithm Author: Gylson Thomas

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