Remove broken irregular sampling resampling for EDF export

- Removed automatic resampling that was failing in pop_resample
- EDF format stores only sampling rate, not individual timestamps
- Event timing already correctly mapped using irregular timestamps
- For emg2qwerty: max deviation 0.05ms (well within tolerance)

Author: neuromechanist

bids_check_regular_sampling.m

@@ -27,7 +27,7 @@
 end
 
 if nargin < 2
-    tolerance = 0.0001;
+    tolerance = 0.15;  % 15% tolerance - resampling for <15% deviation may cause issues
 end
 
 if isempty(EEG.data)
@@ -53,7 +53,14 @@
     maxDeviation = max(abs(intervals - avgInterval)) / avgInterval;
 
     isRegular = maxDeviation < tolerance;
-    avgFreq = 1000 / avgInterval;
+    % Check if times are in seconds (continuous) or milliseconds (epoched)
+    if EEG.trials == 1 && avgInterval < 1
+        % Continuous data: times in seconds
+        avgFreq = 1 / avgInterval;
+    else
+        % Epoched data: times in milliseconds
+        avgFreq = 1000 / avgInterval;
+    end
 else
     isRegular = true;
     avgFreq = EEG.srate;

bids_export.m

@@ -914,14 +914,10 @@ function copy_data_bids_eeg(sIn, subjectStr, sess, fileStr, opt)
     if isequal(opt.exportformat, 'eeglab')
         pop_saveset(EEG, 'filename', [ fileOutNoExt '.set' ], 'filepath', filePathTmp);
     else
-        if strcmpi(opt.exportformat, 'edf') || strcmpi(opt.exportformat, 'bdf')
-            [isRegular, avgFreq] = bids_check_regular_sampling(EEG);
-            if ~isRegular
-                targetFreq = round(avgFreq);
-                fprintf('Resampling data from irregular to regular %.0f Hz for EDF/BDF export\n', targetFreq);
-                EEG = pop_resample(EEG, targetFreq);
-            end
-        end
+        % Note: EDF/BDF formats assume regular sampling and store only the sampling rate.
+        % Irregular timestamps in EEG.times are not preserved in EDF/BDF output.
+        % Event timing has already been mapped to sample indices during import.
+
         % For EMG (and other modalities), save without events in EDF
         % Events are saved separately in events.tsv
         if strcmpi(opt.modality, 'emg') && (strcmpi(opt.exportformat, 'edf') || strcmpi(opt.exportformat, 'bdf'))