[FieldTrip] problem with clusterplot?

[veniero at med.unibs.it]

Dear Jörn,
I'm copmparing two conditions gavgM1_post5 and gavgM1_pre5.
Here the settings I'm using:

cfg = [];
cfg.channel          = {'EEG'};
cfg.layout= 'biosemi64.lay';
cfg.latency          = 'all';
cfg.frequency        = [20 20];
cfg.avgeoverfreq     = 'yes';
cfg.method           = 'montecarlo';
cfg.statistic        = 'indepsamplesT';
cfg.correctm         = 'cluster';
cfg.clusteralpha     = 0.05;
cfg.clusterstatistic = 'maxsum';
cfg.minnbchan        = 2;
cfg.tail             = 0;
cfg.clustertail      = 0;
cfg.alpha            = 0.025;
cfg.numrandomization = 500;
design = zeros(1,size(gavgM1_post5.powspctrm,1) +
size(gavgM1_pre5.powspctrm,1));
design(1,1:size(gavgM1_post5.powspctrm,1)) = 1;
design(1,(size(gavgM1_post5.powspctrm,1)+1):(size(gavgM1_post5.powspctrm,1)+...
  size(gavgM1_pre5.powspctrm,1))) = 2;
cfg.design           = design;
cfg.ivar             = 1;

[stat] = ft_freqstatistics(cfg, gavgM1_post5, gavgM1_pre5);


For the clusterplot:
stat.raweffect = gavgM1_post5.powspctrm - gavgM1_pre5.powspctrm;

cfg = [];
cfg.alpha  = 0.025;
cfg.zparam = 'raweffect';
cfg.zlim   = [-1 1];
cfg.layout = 'biosemi64.lay';
ft_clusterplot(cfg, stat);

Many thanks,
Mimma



> Dear Mimma,
>
> Most likely, you specified a different alpha when calling
> ft_freqstatistics than when calling ft_clusterplot. Could you paste the
> cfg settings for both functions here, so that we can try to track down
> where exactly this error comes from?
>
> Best,
> Jörn
>
>
> On 4/1/2012 7:03 PM, veniero at med.unibs.it wrote:
>> Dear FieldTrip  users,
>> I'm trying to run a cluster-based permutation tests on time-frequency
>> data. I get the result:
>> found 1 positive clusters in observed data found 0 negative clusters in
>> observed data, but I'm not able to use clusterplot because if the
>> following error:
>> ??? Error using ==>  ft_clusterplot at 171
>> no clusters present with a p-value lower than the specified alpha,
>> nothing
>> to plot
>>
>> Is this possible? Maybe it's just a trivial question.
>>
>> Many thanks,
>> Mimma
>>
>>
>> _______________________________________________
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>> fieldtrip at donders.ru.nl
>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>
>
> --
> Jörn M. Horschig
> PhD Student
> Donders Institute for Brain, Cognition and Behaviour
> Centre for Cognitive Neuroimaging
> Radboud University Nijmegen
> Neuronal Oscillations Group
>
> P.O. Box 9101
> NL-6500 HB Nijmegen
> The Netherlands
>
> Contact:
> E-Mail: jm.horschig at donders.ru.nl
> Tel:    +31-(0)24-36-68493
> Web: http://www.ru.nl/donders
>
> Visiting address:
> Trigon, room 2.30
> Kapittelweg 29
> NL-6525 EN Nijmegen
> The Netherlands
>
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