??? Index exceeds matrix dimensions.

Dear all,

I'm new here and I'm adjusting a script from someone else to fit my needs. I keep getting an error while running this script: ??? Index exceeds matrix dimensions.

I'm sorry to bother with what may be a silly question, but I'm a true newbie.

%--------------------------------------------------------------------------
%                         CONFIRM BAD TRIALS
%                          FIND BAD CHANNELS
%--------------------------------------------------------------------------
clear all
addpath(genpath('C:\Program Files (x86)\MATLAB\R2011a\toolbox\fieldtrip20120404'))
cd 'D:\EMCL\MY THESIS\EEG PT\DATA\'
InfoSubjects
InfoExperiment
[rw,cl] = size (Infosubjects); clear cl
for j  =  1:rw
    %----------------------------------------------------------------------
    % LOAD EVENTS AND TRL
    %----------------------------------------------------------------------
    load(sprintf('%s%s%s',info.expname,Infosubjects{j,2},'\EVENTS.mat'));
    load(sprintf('%s%s%s',info.expname,Infosubjects{j,2},'\TRL.mat'));
    hdr = ft_read_header(sprintf('%s%s\\%s\\%s%s',info.expname,Infosubjects{j,2},Infosubjects{j,3},Infosubjects{j,2},info.filename));
    %----------------------------------------------------------------------
    % CONFIRM BAD TRIALS AND FIND BAD CHANNELS
    %----------------------------------------------------------------------
    cfg = [];
    cfg.dataset = sprintf('%s%s\\%s\\%s%s',info.expname,Infosubjects{j,2},Infosubjects{j,3},Infosubjects{j,2},info.filename);

      Trl_p = []; cfg.trl = [0 0 0];
      for c = 1:info.conditions.number
          Trl_p = Trl{c}; cfg.trl = [cfg.trl;Trl_p];
      end
      clear Trl_p
      cfg.trl = cfg.trl(2:length(cfg.trl),:); cfg.channel = hdr.label(1:info.nC);
      cfg.blc = 'yes'; Confirm = ft_preprocessing(cfg);
      cfg = []; cfg.method = 'summary'; Confirm = ft_rejectvisual(cfg, Confirm);

      Channels_good = Confirm.label; Bad_Channels={}; i=1; p=1;
      while i < length(Confirm.cfg.channel)
          if strcmp (Confirm.cfg.channel(i,1),Confirm.label(p,1));
              i = i + 1; p = p + 1;
          else
              Bad_Channels(end+1,:)= Confirm.cfg.channel(i,1);
              i = i + 1;
          end
      end
      clear Channels Channels_good

      juju=[];
      for i = 1:length(Confirm.cfg.trl)-1
          if Confirm.cfg.trl(i,1) > Confirm.cfg.trl(i+1,1)
              juju (end+1, :) = i;
          end
      end
      juju = [0;juju;length(Confirm.cfg.trl)];

      for c = 1:info.conditions.number
          Trl_p = [Confirm.cfg.trl(juju(c)+1:juju(c+1),1:3)];
          Trl{c} = Trl_p;
      end
      clear Trl_p

      %----------------------------------------------------------------------
      % Count and save the trials numbers where were found artifacts
      %----------------------------------------------------------------------
      Trl_p = [];
      for c = 1:info.conditions.number
          for r = 1:info.responses.number
              for i = 1:length(events_clean)
                  if strcmp(num2str(events_clean(i).value), info.conditions.marker(c))
                      % if the experimental condition is defined for more than one marker,
                      % please define here the right criterion and appdate in InfoExperiment info.conditions
  %                     if strcmp(num2str(events_clean(i+info.mbsr).value), info.responses.correct.marker(r))
                          begsample = events_clean(i).sample + info.begintime*hdr.Fs;
                          endsample = events_clean(i+info.mbsr).sample + 0*hdr.Fs - 1;
                          offset = + info.begintime*hdr.Fs;
                          Trl_p(end+1, :) = round([begsample endsample offset]);
                      end
                  end
              end
          end
      end
      Trl_p = sortrows(Trl_p);
      clear i begsample endsample offset events_clean

      [f,u] = size(Confirm.cfg.artifact); Last_Rejected=[];
      for i =1:length(Trl_p);
          for p = 1:f
              if Trl_p(i,1) == Confirm.cfg.artifact(p,1);
                  Last_Rejected(end+1,:) = i;
              end
          end
      end

      Artifacts = Confirm.cfg.artifact;
      if isempty(Artifacts)
          Artifacts = 'no additional trials rejected'; Last_Rejected = 0;
      end
      clear Trl_p c f i Confirm p u juju cfg
      %----------------------------------------------------------------------
      % SAVE THE NUMBER OF TRIALS IN AN EXCEL FILE
      % SAVE THE Artifacts_Conf.mat
      % SAVE THE Bad_Channels.mat
      %----------------------------------------------------------------------
      cd(sprintf('%s%s\\%s',info.expname,Infosubjects{j,2},Infosubjects{j,4}));
      xlswrite('rejectedtrials.xls', Last_Rejected, 'Last_Rejected');
      save Artifacts_Conf Artifacts
      save Bad_Channels Bad_Channels
      cd(sprintf('%s\\%s',info.expname,Infosubjects{j,2}));
      save TRL Trl
  end

Answer 1

[Sargondjani]

the error says that matlab tries to evaluate an element in an array, but the array is smaller than the index it tries to acces...

you should try to figure out why (if you want help on this, you need to make clear in which line the error occured)

you can also put a 'dbstop' before the line in which the error occured. you can than see what is in the workspace and check the dimensions of the matrices that are accessed in the line with the error