[Eeglablist] T-F analysis, help with frequency range

[Makoto Miyakoshi]

Dear Xianghong and Clemens,

I guess Xianghong used wrong parameters.

> We want to see the range at least from 1 Hz to 50 Hz,

Then you have to have 5-6 sec epoch length! This is because if you want to
use (and you do want to use) 3 cycles at the lowest frequency of 1 Hz, your
sliding window length will be 3 sec long. Your 1-Hz resolution will be very
blurry because of this. Also, using 5-6 sec epoch length is not very common
(usually -1 to 2 sec which we recommend; and use 3Hz with 3 cycle).

See slide 21 of this file to understand the parameters.
http://sccn.ucsd.edu/mediawiki/images/1/19/C2_A3_Time-frequencyDecAndAdvancedICAPracticum.pdf

Makoto

On Mon, Jul 20, 2015 at 12:46 AM, Clemens DICKHUT <clemens.dickhut at uni.lu>
wrote:

>  Hi Xianghong,
>
>  if you are using the imagesc function to plot, you just need to adjust
> the axis parameters,
> for example
>
>
>  imagesc((analysis.ERP.times), (ERP.freqs), GROUP_ERSP)
> axis([-700 700 2 50])
>  set(gca,'YDir','normal')
>  title('ERSP Congruent' ,'FontSize',17);
>
>  if you use the newtimef function you have to specify the parameters in
> the function, such as ‘maxfreq':
>
>
> https://sccn.ucsd.edu/svn/software/branches/eeglab11/functions/timefreqfunc/newtimef.m
>
>  Best,
> Clemens
>
>
>   On 17 Jul 2015, at 00:34, Xianghong <xianghong at hmri.org> wrote:
>
> Hi,
>
> I try to use their time-frequency analysis, by using the
> plot/time-frequency transforms/channel time-frequency. However, the figure
> generated only show the frequency range of 15-50 Hz. We want to see the
> range at least from 1 Hz to 50 Hz, how to rescale the T-F plot?
> Thanks,
> Best,
>
> Xianghong
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
>
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>



-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20150723/f8be4d45/attachment.html>