megplanar input structure

[Akiko Ikkai]

Thank you very much for suggestions earlier. Visualization of the ERF using planar gradient runs smoothly (with cfg.keeptrials = 'no';).

I'm now trying to run cluster-based permutation tests on ERF with planar gradient, following the tutorial. I'm confused with what the input structure should look like.

My confusions come from the difference between figure1 (tutorial:cluster_permutation_erf:clusperm_erf_anaprot_stat_planar_ficvsfc.png) and the middle part of the tutorial page ("Using planar gradient data" in cluster_permutation_timelock). In figure, there is additional timelockanalysis between megplanar and combineplanar, whereas in the main text, combineplanar directly follows megplanar.

I tried 3 things: 1. Without timelockanalysis (after megplanar), I get an error in permutation with an input
ERF1 =

      trial: {1x137 cell}
      label: {157x1 cell}
       grad: [1x1 struct]
    fsample: 500
       time: {1x137 cell}
        cfg: [1x1 struct]

[stat] = timelockstatistics(cfg, ERF1, ERF2);

??? Reference to non-existent field 'dimord'.

Error in ==> prepare_timefreq_data>forcedimord at 577
inputdim  = tokenize(input.dimord, '_');

Error in ==> prepare_timefreq_data at 176
  [remember{c}, hascrsspctrm] = forcedimord(varargin{c});

Error in ==> statistics_wrapper at 318
  [cfg, data] = prepare_timefreq_data(cfg, varargin{:});

Error in ==> timelockstatistics at 115
[stat, cfg] = statistics_wrapper(cfg, varargin{:});

Error in ==> cluster_ERF_bwTrialtest_planar at 50
[stat] = timelockstatistics(cfg, ERF1, ERF2);

2. manually added dimord to the same input
ERF1.dimord = 'rpt_chan_time';

[stat] = timelockstatistics(cfg, ERF1, ERF2);

??? Undefined function or method 'isnan' for input arguments of type 'cell'.

Error in ==> prepare_timefreq_data at 215
  if isempty(findstr(remember{c}.dimord, 'time')) || all(isnan(remember{c}.time))

Error in ==> statistics_wrapper at 318
  [cfg, data] = prepare_timefreq_data(cfg, varargin{:});

Error in ==> timelockstatistics at 115
[stat, cfg] = statistics_wrapper(cfg, varargin{:});

3. With timelockanalysis (after megplanar), it crashes during combineplanar

??? Subscripted assignment dimension mismatch.

Error in ==> checkdata>raw2timelock at 1136
    tmptrial(i,:,begsmp(i):endsmp(i)) = data.trial{i};

Error in ==> checkdata at 366
        data = raw2timelock(data);

Error in ==> combineplanar at 356
    data = checkdata(data, 'datatype', 'timelock', 'feedback', 'yes');


... so, I'm trying to figure out what input structure timelockstatistics requires in order to run with planar gradient. I'm converting all inputs to single in order to avoid memory error, but I don't think that is the cause of the problem.

Thanks in advance! Akiko


----- Original Message -----
From: jan-mathijs schoffelen <jan.schoffelen at DONDERS.RU.NL>
Date: Tuesday, September 21, 2010 5:37 am
Subject: Re: [FIELDTRIP] megplanar input structure
To: FIELDTRIP at NIC.SURFNET.NL

> Dear Akiko,
>
> I think that your crash may be related to the issue of missing
> channels. Antony already pointed you to a way how to fix this. As to
>
> your first question: ft_megplanar indeed works with data containing a
>
> trial field (as cell-array). However, no need for you to worry about
>
> this; if your input data is for example a 'timelock' structure,
> fieldtrip automatically converts this structure into one containing a
>
> 'trial'.
>
> Best wishes,
>
> Jan-Mathijs

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