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Re: query about function output
Posted:
Dec 25, 2013 11:07 AM


"Loren Shure" wrote in message <l9c8pl$sqb$1@newscl01ah.mathworks.com>... > "Dhanashree " <dhanurane17@gmail.com> wrote in message > news:l9bb9t$kbi$1@newscl01ah.mathworks.com... > > y=abs(x_fft(1:M/2,:)); > > imagesc(t,f,dB(y)) > > > > imagesc gives me the spectrogram.that is i have used that function to plot > > the spectrogram.y is giving the magnitude of the fft calculated.In the > > above function what does dB(y) do? when i use only y i get complete ble > > coloured spectrogram.plz help. > > > > dB is either a function that you have or a variable you haven't shown us > yet. It looks like it's meant to be a decibel calculation, but without the > code, hard to say... > > > >  > Loren > > http://blogs.mathworks.com/loren ok.....i am giving you the whole program i have.It is basically program to plot spectrogram.plz explain it to me.
M=256; B=floor(N/M); x_mat=reshape(x(1:M*B),[M B]); hamming(M); win_mat=repmat(hamming(M),[1 B]); x_fft=(x_mat.*win_mat); y=abs(x_fft(1:M/2,:)); t=(1:B)*(M/fs); f=((0:M1)/(M1)*(fs/2)); f; %bark=frq2bark(f); %bark=13.*atan(0.00076*f)+3.5.*atan((f/7500)^2); figure(2); imagesc(t,f,dB(y)); colormap(jet); colorbar; set(gca,'ydir','normal'); xlabel('Time(sec)'); ylabel('Frequency(Hz)'); title('Spectrogram');



