using clusterrandanalysis with avgtime = 'yes'

Andre Bastos abastos at BERKELEY.EDU
Sat Apr 14 03:11:30 CEST 2007

Dear Trippers,

So I am studying the differences in ongoing data between two experimental
conditions. Because the data are not time-locked and the differences I
expect are between conditions and not necessarily a function of time, it
doesn't quite make sense to have a dynamic power spectrum. I have been
performing the cluster analysis with my 4-dimensional data
(rpt_chan_freq_time), but this still produces clusters that are
time-dependent. I set cfg.avgtime = 'yes', but now cluster.stats and
.raweffects (and everything else produced by clusterrandanalysis) are NaNs.

Here is my cfg:

  cfg.statistic = 'indepsamplesT';
  cfg.alphathresh = 0.05;
  cfg.makeclusters = 'yes';
  cfg.minnbchan = 2;
  cfg.clusterteststat = 'maxsum';
  cfg.onetwo = 'twosided';
  cfg.alpha = 0.05;
  cfg.nranddraws = 200; = 'all';
  cfg.elec = TFR1.elec;
  cfg.neighbourdist    = 49;
  cfg.avgovertime = 'yes';

I execute:
[clusrand] = clusterrandanalysis(cfg, TFR1, TFR2);

Here is the Matlab output:
Selecting and formatting the data.
selected 64 channels
averaging over 97 time bins
selected 40 frequency bins
Calculating the neighbourhood structure of the channels.
Obtaining the electrode configuration from the configuration.
Running the statistics engine.
Statistic-specific preprocessing (calculating critical values, initializing
draws from the randomization distribution, ...).
randomization 0 200
randomization 1 200
randomization 2 200

The script executes, runs pretty fast, and then produces a cluster structure
with all NaNs.

Anyone know what I am doing wrong?



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