fiff_read_epochs

 [epochs] = fiff_read_epochs(fname,setno)

 Read eochs from file


   Author : Martin Luessi, MGH Martinos Center
   License : BSD 3-clause

0001 function [epochs] = fiff_read_epochs(fname)
0002 %
0003 % [epochs] = fiff_read_epochs(fname,setno)
0004 %
0005 % Read eochs from file
0006 %
0007 %
0008 %   Author : Martin Luessi, MGH Martinos Center
0009 %   License : BSD 3-clause
0010 
0011 global FIFF;
0012 if isempty(FIFF)
0013     FIFF = fiff_define_constants();
0014 end
0015 
0016 me='MNE:fiff_read_epochs';
0017 
0018 %
0019 %   Open the file
0020 %
0021 fprintf(1,'Reading %s ...\n',fname);
0022 [ fid, tree ] = fiff_open(fname);
0023 %
0024 %   Read the measurement info
0025 %
0026 [ info, meas ] = fiff_read_meas_info(fid,tree);
0027 info.filename = fname;
0028 
0029 %
0030 %   Read events
0031 %
0032 [ events, mappings ] = fiff_read_events(fid,tree);
0033 
0034 %
0035 % Locate the data of interest
0036 %
0037 processed = fiff_dir_tree_find(meas, FIFF.FIFFB_PROCESSED_DATA);
0038 if length(processed) == 0
0039         fclose(fid);
0040     error(me,'Could not find epochs data');
0041 end
0042 
0043 ep = fiff_dir_tree_find(meas, FIFF.FIFFB_EPOCHS);
0044 if length(ep) == 0
0045         fclose(fid);
0046     error(me,'Could not find epochs data');
0047 end
0048 
0049 comment = '';
0050 selection = '';
0051 drop_log = '';
0052 for k = 1:ep.nent
0053     kind = ep.dir(k).kind;
0054     pos  = ep.dir(k).pos;
0055     switch kind
0056         case FIFF.FIFF_FIRST_SAMPLE
0057             tag = fiff_read_tag(fid,pos);
0058             first = tag.data;
0059         case FIFF.FIFF_LAST_SAMPLE
0060             tag = fiff_read_tag(fid,pos);
0061             last = tag.data;
0062         case FIFF.FIFF_COMMENT
0063             tag = fiff_read_tag(fid,pos);
0064             comment = tag.data;
0065         case FIFF.FIFF_EPOCH
0066             tag = fiff_read_tag(fid,pos);
0067             epoch = tag.data;
0068         case FIFF.FIFF_MNE_BASELINE_MIN
0069             tag = fiff_read_tag(fid,pos);
0070             bmin = tag.data;
0071         case FIFF.FIFF_MNE_BASELINE_MAX
0072             tag = fiff_read_tag(fid,pos);
0073             bmax = tag.data;
0074         case FIFF.FIFFB_MNE_EPOCHS_SELECTION
0075             tag = fiff_read_tag(fid,pos);
0076             selection = tag.data;
0077         case FIFF.FIFFB_MNE_EPOCHS_DROP_LOG
0078             tag = fiff_read_tag(fid,pos);
0079             drop_log = tag.data;
0080     end
0081 end
0082 
0083 if ~exist('epoch','var')
0084     fclose(fid);
0085     error(me,'Epochs data not found');
0086 end
0087 
0088 if ~exist('bmin','var')
0089     bmin = double(first)/info.sfreq;
0090 end
0091 
0092 if ~exist('bmax','var')
0093     bmax = double(last)/info.sfreq;
0094 end
0095 
0096 baseline = [bmin, bmax];
0097 
0098 nsamp = last-first+1;
0099 fprintf(1,'\tFound the data of interest:\n');
0100 fprintf(1,'\t\tt = %10.2f ... %10.2f ms (%s)\n',...
0101     1000*double(first)/info.sfreq,1000*double(last)/info.sfreq,comment);
0102 if ~isempty(info.comps)
0103     fprintf(1,'\t\t%d CTF compensation matrices available\n',length(info.comps));
0104 end
0105 
0106 if size(epoch,1) ~= size(events,1)
0107     fclose(fid);
0108     error(me,'Incorrect number of trials (%d instead of %d)',...
0109         size(epoch,1),size(events,1));
0110 end
0111 
0112 if size(epoch,2) ~= info.nchan
0113     fclose(fid);
0114     error(me,'Incorrect number of channels (%d instead of %d)',...
0115         size(epoch,2),info.nchan);
0116 end
0117 
0118 if size(epoch,3) ~= nsamp
0119     fclose(fid);
0120     error(me,'Incorrect number of samples (%d instead of %d)',...
0121         size(epoch,3),nsamp);
0122 end
0123 
0124 %
0125 %   Calibrate
0126 %
0127 for k = 1:info.nchan
0128     cals(k) = info.chs(k).cal;
0129 end
0130 
0131 nepochs = size(epoch, 1);
0132 epoch = repmat(cals, [nepochs, 1, nsamp]) .* epoch;
0133 
0134 times = double(first:last) / info.sfreq;
0135 tmin = times(1);
0136 tmax = times(end);
0137 
0138 %
0139 % Put it all together
0140 %
0141 epochs.info = info;
0142 epochs.events = events;
0143 epochs.name = comment;
0144 epochs.times = times;
0145 epochs.tmin = tmin;
0146 epochs.tmax = tmax;
0147 epochs.data = epoch;
0148 epochs.baseline = baseline;
0149 epochs.event_id = mappings;
0150 epochs.selection = selection;
0151 epochs.drop_log = drop_log;
0152 
0153 fclose(fid);
0154 
0155 return;