Problems with frequency analysis...

[Carina Graversen]

Hi Jan.

Thanks for your reply - that helped quite a lot  :o).

However, now I have another problem, when I want to plot the
time-frequency results. I use the code below, and as you will notice I
just load an .avg file, and overwrite all the data in the file to be a
single sinusoid with a frequency of 5 Hz.

However, the results I get from multiplotTFR doesn't look as expected :o(

The data I put in dataFIC.trial for all channels can be watched at:
http://www.hst.auc.dk/~cgra/fieldtrip_timeplot.jpg

And the result from multiplot TFR can be seen at:
http://www.hst.auc.dk/~cgra/fieldtrip_multiplotTFR.jpg

- where I of course would have expected to have high power for all time
instances at a frequency of 5 Hz. So I was wondering if anyone can tell
which parameter to change in my configuration variables :o).

Best regards, Carina







function [] = diabetestest()

close all
clear all
clc

cfg1                                    = [];
cfg1.datafile                           = 'diabetestest.avg'
cfg1.headerfile                         = 'diabetestest.avg'

dataFIC                                 = preprocessing(cfg1);

% *************************************************************************
% ------------------------------ DEBUG CODE ------------------------------
% *************************************************************************

test_frequency   =    5;      % Test frequency
sample_frequency = 1000;      % Sample frequency

% Generating the dummy signal:
for i = 1:301
     dummy_signal(i)= 5*sin(2*pi*test_frequency*i/sample_frequency);
end

for i = 1:1:68
  dummy_matrix(i, :) = dummy_signal;  end

dataFIC.trial{1} = dummy_matrix;

figure(101)
plot(dummy_matrix(1, :), 'r')

% *************************************************************************
% --------------------------- END OF DEBUG CODE ---------------------------
% *************************************************************************

cfg2                                    = [];
cfg2.method                             = 'wltconvol'; %= 'mtmconvol';
cfg2.output                             = 'pow';
cfg2.channel                            = 'all';
cfg2.foi                                = 0.1:0.05:20;
cfg2.toi                                = 0.050:0.001:0.300
cfg2.width                              = 0.0005;

TFRhann                                 = freqanalysis(cfg2, dataFIC);

% -------------------------------------------------------------------------

cfg3.zparam     = 'powspctrm';
cfg3.xlim       = [0.050 0.300];
cfg3.ylim       = [1 10];
cfg3.layout     = 'testlay_64.lay';
cfg3.showlabels = 'yes';

multiplotTFR(cfg3, TFRhann)

% -------------------------------------------------------------------------

% cfg4 = [];
% cfg4.channel   = 'FP1';
% clf
% % singleplotTFR(cfg4, TFRhann);

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