color bar not agreeing with data

[Jim Li]

Hi Saskia,

You're right on the point! Thanks a lot for your help, :)

Jim

On Wed, 29 Jul 2009 18:55:48 +0200, Saskia Haegens 
<saskia.haegens at DONDERS.RU.NL> wrote:

>Hi Jim,
>
>Does your data contain a repetition dimension (i.e. did you run freqanalysis
>with cfg.keeptrials='yes')? In that case, when you don't specify which
>trials to plot, the plotting functions such as multiplotTFR will plot the
>average over all trials. This could explain the discrepancy you describe.
>
>Best,
>Saskia
>
>> -----Original Message-----
>> From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On
>> Behalf Of Jim Li
>> Sent: 29 July 2009 18:11
>> To: FIELDTRIP at NIC.SURFNET.NL
>> Subject: [FIELDTRIP] color bar not agreeing with data
>>
>> Dear Fieldtripper:
>>
>> I am puzzled by the output from "multiplotTFR". The colorbar doesn't look
>> right
>> at all! Can anyone help me?
>>
>> Basicly I have a data structure caled "TF" that's calculated from
>> FREQANALYSIS. I ran the following script and got a plot (see attachment)
>>
>> -----------------------------
>> >> cfg              = []; cfg.layout  = '4D248.lay'; cfg.interactive  =
>> 'yes';
>> cfg.showlabels = 'yes';
>> cfg.colorbar      = 'yes'; cfg.renderer=  'zbuffer'
>> figure;
>> multiplotTFR(cfg,TF);
>>
>> cfg =
>>
>>          layout: '4D248.lay'
>>     interactive: 'yes'
>>      showlabels: 'yes'
>>        colorbar: 'yes'
>>        renderer: 'zbuffer'
>>
>> the input is freq data with 248 channels, 141 frequencybins and 77
>> timebins
>> reading layout from file 4D248.lay
>> >>
>> ------------------------------
>>
>> Now, when running " max(max(max(max(TF.powspctrm(:,:,:,:)))))" I got :
>>
>> -------------
>> ans =
>>
>>     2.287227537931770e-023
>> --------------
>>
>> This is order of magnitude larger than the colorbar maximum, which is
>> 1.82e-
>> 24 (see attachment) . Why should this discrepency happen? Why the data
>> maximum is not plotted?
>>
>>
>> The same happened to the minimum: when running "min(min(min(min
>> (TF.powspctrm(:,:,:,:)))))" I got  5.393784644607502e-034, which is about
>> 8
>> orders of magnitude smaller than the colorbar minimum (2.12e-26 according
>> to
>> the attached figure). This I can understand since small numbers should be
>> sacrificed to  save bandwidth for more significant numbers.
>>
>>
>> BTW I tried "singleplotTFR" and got the same discrepency between data
>> maximum and plot/colorbar maximum for a channel. They differ by about an
>> order of magnitude, which is huge!
>>
>> FYI, I was working directly before my PC, not through VNC or Remote
>> Desktop connection.
>>
>> Thanks a lot,
>>
>> Jim
>>
>> ----------------------------------
>> The aim of this list is to facilitate the discussion between users of the
>> FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG
>> and EEG analysis. See also
>> http://listserv.surfnet.nl/archives/fieldtrip.html and
>> http://www.ru.nl/neuroimaging/fieldtrip.
>
>----------------------------------
>The aim of this list is to facilitate the discussion between users of the 
FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and 
EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and 
http://www.ru.nl/neuroimaging/fieldtrip.

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.