Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
strange behaviour of spectrogram

Subject: strange behaviour of spectrogram

From: RoK

Date: 11 Aug, 2010 15:25:46

Message: 1 of 3

Hi,
I am using the spectrogram function of matlab and I am some problems for
understanding its behaviour:

S = spectrogram(x,[],[],512);

for
t = 0:0.01:26;
x = cos(8*pi*t) + cos(16*pi*t);

it gives me S with 257 rows
while for other kind of signals x S becomes with 512 rows (as I ask)

Is there any reason for that?
Thanks for your help

RoK



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Subject: strange behaviour of spectrogram

From: RoK

Date: 11 Aug, 2010 16:11:07

Message: 2 of 3


"RoK" <rrtesdfsdfbdgsdgsdf@hotmail.com> ha scritto nel messaggio
news:i3ufe8$1foe$1@adenine.netfront.net...
> Hi,
> I am using the spectrogram function of matlab and I am some problems for
> understanding its behaviour:
>
> S = spectrogram(x,[],[],512);
>
> for
> t = 0:0.01:26;
> x = cos(8*pi*t) + cos(16*pi*t);
>
> it gives me S with 257 rows
> while for other kind of signals x S becomes with 512 rows (as I ask)
>
> Is there any reason for that?
> Thanks for your help
>
> RoK
>
>

I try to give an answer, the other signal I was trying with was complex.
Sorry

RoK



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Subject: strange behaviour of spectrogram

From: Wayne King

Date: 11 Aug, 2010 16:35:18

Message: 3 of 3

"RoK" <rrtesdfsdfbdgsdgsdf@hotmail.com> wrote in message <i3ui3b$1l20$1@adenine.netfront.net>...
>
> "RoK" <rrtesdfsdfbdgsdgsdf@hotmail.com> ha scritto nel messaggio
> news:i3ufe8$1foe$1@adenine.netfront.net...
> > Hi,
> > I am using the spectrogram function of matlab and I am some problems for
> > understanding its behaviour:
> >
> > S = spectrogram(x,[],[],512);
> >
> > for
> > t = 0:0.01:26;
> > x = cos(8*pi*t) + cos(16*pi*t);
> >
> > it gives me S with 257 rows
> > while for other kind of signals x S becomes with 512 rows (as I ask)
> >
> > Is there any reason for that?
> > Thanks for your help
> >
> > RoK
> >
> >
>
> I try to give an answer, the other signal I was trying with was complex.
> Sorry
>
> RoK
>
>
>
> --- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Hi Rok, You answered your own question :) For complex-valued signals, there's no assumption that the magnitude response is an even function of frequency.

Wayne

Tags for this Thread

No tags are associated with this thread.

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us