MATLAB Central Newsreader - how to create waterfall plot

how to create waterfall plot

Clement Lim — Sat, 29 Aug 2009 14:32:03 -0400

Hi All,

I had the following script to read a .wav file and plot the spectrogram of the signal generated.

>> [filename, pathname] = uigetfile('*.*', 'Pick any file');
>> [y, fs, nbits] = wavread(filename);
>> spectrogram(y);

I would like to modify the code so that it can analyse and plot the music file both from .wav and from a music cd. Furthermore, I would also like to show a waterfall plot of the spectrogram. Can anyone help me or provide me with an example?

Thanks a million!

Re: how to create waterfall plot

us — Sat, 29 Aug 2009 14:44:03 -0400

Re: how to create waterfall plot

us — Sat, 29 Aug 2009 15:08:03 -0400

"us "
> > I would like to modify the code so that it can analyse and plot the music file both from .wav and from a music cd. Furthermore, I would also like to show a waterfall plot of the spectrogram. Can anyone help me or provide me with an example?
> >
> > Thanks a million!
>
> a hint:
>
> help waterfall;

sorry, forgot the ...example... part...

     d=load('chirp');
     [ff,ff,tt,pxx]=spectrogram(d.y);
     subplot(2,1,1);
     spectrogram(d.y);
     subplot(2,1,2);
     arg={ff,tt,10*log10(abs([pxx.'])+eps)};
     waterfall(arg{:});
     colormap(jet(256));

us

Re: how to create waterfall plot

Clement Lim — Sat, 29 Aug 2009 15:22:03 -0400

"us " <us@neurol.unizh.ch> wrote in message <h7bg8j$afj$1@fred.mathworks.com>...
> "us "
> > > I would like to modify the code so that it can analyse and plot the music file both from .wav and from a music cd. Furthermore, I would also like to show a waterfall plot of the spectrogram. Can anyone help me or provide me with an example?
> > >
> > > Thanks a million!
> >
> > a hint:
> >
> > help waterfall;
>
> sorry, forgot the ...example... part...
>
> d=load('chirp');
> [ff,ff,tt,pxx]=spectrogram(d.y);
> subplot(2,1,1);
> spectrogram(d.y);
> subplot(2,1,2);
> arg={ff,tt,10*log10(abs([pxx.'])+eps)};
> waterfall(arg{:});
> colormap(jet(256));
>
> us

Hi us,

Tks for the prompt reply. However the above code does not allow me to analyse in term of a music cd. That mean, I would like the script to prompt the user to input in the file to analyse. Currently, my original code is only able to analyse .wav files. However, it wont work for .wma file.
Furthermore, it is possible for the waterfall plot to animate as a function of time when the music is being play?

Pls advise tks.

Re: how to create waterfall plot

us — Sat, 29 Aug 2009 15:50:18 -0400

"Clement Lim"
> Tks for the prompt reply. However the above code does not allow me to analyse in term of a music cd. That mean, I would like the script to prompt the user to input in the file to analyse. Currently, my original code is only able to analyse .wav files. However, it wont work for .wma file.
> Furthermore, it is possible for the waterfall plot to animate as a function of time when the music is being play?
>
> Pls advise tks.

as far as i know, reading WMA files into ML currently can only be achieved by the signal proc blockset (an extension of SL) module FROM-MULTIMEDIA-FILE...
thus, you could ...try(!)... to create a SL model to do what you want; although i doubt that the current hardware is physically able to generate a waterfall plot of a moving spectrogram in real-time...
however, others will know more (and better)...

us

how to show filename in GUI

BC Tan — Sun, 30 Aug 2009 10:02:01 -0400

Hi All,

I have the following code to read in the filename of the music file.

[filename, pathname] = uigetfile('*.*', 'Pick any file');
[y, fs, nbits] = wavread(filename);
handles.value = filename;

I had created a GUI and had placed a static text with tag being "tSource".
I would like to show the filename of the file that the users had chosen in the GUI with the following code.

set(handles.tSource,'String',sprintf('%s:%d',handles.value,handles.id));

However, the code is unable to show the filename as predicted. can anyone tell me what is wrong with my code?

Tks a million!

Re: how to create waterfall plot

asdafa — Wed, 28 Oct 2009 03:44:02 -0400

"Clement Lim" <clementlim@singnet.com.sg> wrote in message <h7be53$kjl$1@fred.mathworks.com>...
> Hi All,
>
> I had the following script to read a .wav file and plot the spectrogram of the signal generated.
>
> >> [filename, pathname] = uigetfile('*.*', 'Pick any file');
> >> [y, fs, nbits] = wavread(filename);
> >> spectrogram(y);
>
> I would like to modify the code so that it can analyse and plot the music file both from .wav and from a music cd. Furthermore, I would also like to show a waterfall plot of the spectrogram. Can anyone help me or provide me with an example?
>
> Thanks a million!

Hi, sorry to use your post..I don't know how to crete one..really sorry
I have a problem with your code:
> >> [filename, pathname] = uigetfile('*.*', 'Pick any file');
> >> [y, fs, nbits] = wavread(filename);
> >> spectrogram(y);
I make it run but says:

??? Error using ==> spectrogram at 113
X must be a vector (either row or column).
Error in ==> spec at 3
spectrogram(y);

Can anyone help me with this please, im new in this.
thanks for your help!