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Feature Extraction

Started by icicle January 1, 2008
Hi All,

I have a question about the feature extraction. I used the continuous
wavelet transform(CWT)for my 1D signal and will select the mean and median
frequency as features from that CWT.  My question is how to select these
frequencies from the CWT by using MATLAB.

Thanks in advance


is your 1D signal discrete in nature?

if yes then you can use discrete wavelet transform, to perform
1st level of decomposition. you will get the low frequency and
the high frequency components after performing decimation. you
can then perform operations like averaging (using filter commmand
in matlab) or median operation.

the wavelet decomosition can be done in matlab using the command
[cA,cD] = dwt(X,'wname'), just type help dwt in matlab window and
you will get details about the command.

regards
bharat pathak

Arithos Designs
www.arithos.com




>Hi All, > >I have a question about the feature extraction. I used the continuous >wavelet transform(CWT)for my 1D signal and will select the mean and
median
>frequency as features from that CWT. My question is how to select these >frequencies from the CWT by using MATLAB. > >Thanks in advance > > >