Request for clarrification

[Talsma D]

Hi, 

First of all, let me say that I'm by no means an expert in TF analysis
yet, but since the list is quite these days (due to vacation time), let
me try and have a stab at answering your question. 

The error message you are getting suggests that you only have a 0.2 s
signal, which is likely too small, specifically, because you request the
TF analysis to be conducted between -1 to 1.5 s, which would be an
interval too wide to fit into the 200 ms signal.

I therefore suspect that there might be an error earlier on in reading
in the data, where you may have accidentally read in a much smaller
portion of the data than what you intended to. This is but a guess...

HTH,
Durk



-----Oorspronkelijk bericht-----
Van: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] Namens
rathinaswamy bavanandan govindan
Verzonden: Sunday, July 17, 2005 8:42 PM
Aan: FIELDTRIP at NIC.SURFNET.NL
Onderwerp: [FIELDTRIP] Request for clarrification


Hi,
Greetings!
I am novice to fieldtrip! I am interested in time
frequency analysis of MEG data. Before applying the
software to my data I started with the Tutorial. I am
using version fieldtrip-0.9.6. I just followed the
commands 'Reading the data' in tutorial. I used
Subject01.ds as test case. I could able to preprocess
the data and save the data in dataFIC. Then I followed calculating the
time-frequency representation (TFR) using multitapers! 

cfg.output='pow';
cfg.sgn='all';
cfg.method='convol';
cfg.foi=15:30;
cfg.t_ftimwin=round(dataFIC.fsample.*3./cfg.foi)./dataFIC.fsample;
cfg.t_ftimwin=round(dataFIC.fsample.*3./cfg.foi)./dataFIC.fsample;
cfg.tapsmofrq=round(cfg.foi./5);
cfg.toi=-1:0.01:1.5;
cfg.pad=3;
cfg.keeptrials='no';
cfg.keeptapers='no';
TFRmult=freqanalysis(cfg,dataFIC);

I got the following error message! 

??? Error using ==> freqanalysis_mtmconvol
15.000 Hz : datalength to short for specified
smoothing
datalength: 0.200 s, smoothing: 3.000 Hz, minimum
smoothing: 5.000 Hz

Error in ==> freqanalysis at 176
eval(sprintf('freq = freqanalysis_%s(cfg,data);',lower(cfg.method)));

Error in ==> check at 12
TFRmult=freqanalysis(cfg,dataFIC);



It would be nice if someone could give input on this!

Thanks for attention!

Best regards
Govindan

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com