Matrix indexing within a loop
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Rene Sebena
on 20 Nov 2016
Commented: Walter Roberson
on 20 Nov 2016
Hi there, I have a script which loads epoched eog data (one after another) and identifies the bad trials (horizontal amplitudes above 95mV or bellow -95 mV). What I am just trying to add there, is a code which will be continuosly write into 8*25matrix (8 experimental conditions and 25 trials for each), which trials are good and which are bad, so if it finds eg. in the 9th trial of the first experimental condition bad trial it will write "1", and if not "0". Hope it is clear enough and thank you for your help!
for k = 1:8
% Create a mat filename, and load it into a structure called matData.
matFileName = sprintf('event_%d_chans35-38.mat', k);
if exist(matFileName, 'file')
matData = load(matFileName);
else
fprintf('File %s does not exist.\n', matFileName);
end
xf=diff(matData.dataArray(3:4,:,:),1);
xf=squeeze(xf);
EOG_threshold_min = -95;
EOG_threshold_max = 95;
% Identify trials behind the threshold
max_hor_amplitudes = max(xf); %get max amplitude for each individual trial
min_hor_amplitudes = min(xf); %get min amplitude for each individual trial
bad_max = max_hor_amplitudes > EOG_threshold_max;
bad_min = min_hor_amplitudes < EOG_threshold_min;
bad_trials_max = find(bad_max);
bad_trials_min = find(bad_min);
end
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Accepted Answer
Walter Roberson
on 20 Nov 2016
Change
bad_trials_max = find(bad_max);
bad_trials_min = find(bad_min);
to
bad_trials_max(k, :) = bad_max;
bad_trials_min(k, :) = bad_min;
2 Comments
Walter Roberson
on 20 Nov 2016
The indexing by k ensures that it updates the output matrix, not rewrites all of it.
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