Finding Peaks after Event (in a time frame)

I'm trying to find peaks of a dataset that occur after an event. I've attached a figure to help me explain. I am trying to find the local maximum (red arrows for examples) right after each event (marked by the dotted lines). I think I can use findpeaks for this, but I'm not sure how to set the timeframe. I want to have the following data recorded: [Event label, event time, peak height, time from event to first peak, time of peak (should be the index of the peak)], and I need the electrode label recorded.

The files I actually want to use this on are much larger (like the picture I attached), but even the zip file of one of the datasets was too big to attach, so I'm using this dataset as an example.

%% Importing_and_Plotting_EEG_Example
close all; clear all; clc;
% look to 300 ms for peak after stimulation
% stops Matlab from rounding numbers
format long;

% Importing csv data
    T=readtable('Try 4.csv'); %This reads the csv data into a table named T
    timestampOrig=T.Timestamp; %this makes timestampOrig equal to the original Timestamp
    T.Timestamp=T.Timestamp-T.Timestamp(1); %This changes the official Timestamp column so it is 0 at the start of the recording 
    % Changes the sensor names from EEG_<sensor> to <sensor>
    T.Properties.VariableNames(2:end)=extractAfter(T.Properties.VariableNames(2:end),'_');
    %T5=head(T, 5) %shows first 5 rows of table T
    Int=readtable('Event Marker Try 4_EPOCX_126368_2021.06.04T15.42.31.04.00_intervalMarker.csv');
    EvtMar=Int.latency;
    EvtMarLab=Int.type;
    EvtLab=readtable('Try 4 Event Labels.xlsx');
    table(EvtLab)

If possible, I'd like to use a for loop, similar to the one shown below, so I automate the process of finding the values for all 14 electrodes in certain sections, such as in EO, EC, CE, OM.

 for i=2:width(T) %1 plot for each sensor
      %finds the peaks for each sensor. The peak is currently defined as as
      %point that is at least 100 uV above the values directly to the left
      %and right of the peak value; this also plots the peaks
      findpeaks(T{:,i},T.Timestamp, 'MinPeakProminence', 100) 
      xline(EvtMar,'--',{'EO','BE','BE','BE','EC','BE','CE','CE','BE','OM','OM'});
      %creates ylabel as the sensor names, in bold font
      ylabel(T.Properties.VariableNames(i), 'FontWeight', 'bold')
    end %ends for loop

I have this section of code that I used to find the time between peaks, but it isn't quite what I'm trying to do.

    %% Time Between Peaks
    %Assigns the peak values and indices of peak values to variables
    %<sensor>pk and <sensor>index, respectively
    [AF3pk, AF3index]=findpeaks(T.AF3, T.Timestamp,'MinPeakProminence',mnpkprom); [F7pk, F7index]=findpeaks(T.F7, T.Timestamp,'MinPeakProminence',mnpkprom);
    [F3pk, F3index]=findpeaks(T.F3, T.Timestamp,'MinPeakProminence',mnpkprom); [FC5pk, FC5index]=findpeaks(T.FC5, T.Timestamp,'MinPeakProminence',mnpkprom);
    [T7pk, T7index]=findpeaks(T.T7, T.Timestamp,'MinPeakProminence',mnpkprom); [P7pk, P7index]=findpeaks(T.P7, T.Timestamp,'MinPeakProminence',mnpkprom);
    [O1pk, O1index]=findpeaks(T.O1, T.Timestamp,'MinPeakProminence',mnpkprom); [O2pk, O2index]=findpeaks(T.O2, T.Timestamp,'MinPeakProminence',mnpkprom);
    [P8pk, P8index]=findpeaks(T.P8, T.Timestamp,'MinPeakProminence',mnpkprom); [T8pk, T8index]=findpeaks(T.T8, T.Timestamp,'MinPeakProminence',mnpkprom);
    [FC6pk, FC6index]=findpeaks(T.FC6, T.Timestamp,'MinPeakProminence',mnpkprom); [F4pk, F4index]=findpeaks(T.F4, T.Timestamp,'MinPeakProminence',mnpkprom);
    [F8pk, F8index]=findpeaks(T.F8, T.Timestamp,'MinPeakProminence',mnpkprom); [AF4pk, AF4index]=findpeaks(T.AF4, T.Timestamp,'MinPeakProminence',mnpkprom);
    
        %creates tables of <sensor>Indices and <sensor> Peak Values - different
    %table for each sensor
    AF3tab=table(AF3index, AF3pk, 'VariableNames', {'AF3 Index (s)', 'AF3 Peak (uV)'});
    F7tab=table(F7index, F7pk, 'VariableNames', {'F7 Index (s)', 'F7 Peak (uV)'});
    F3tab=table(F3index, F3pk, 'VariableNames', {'F3 Index (s)', 'F3 Peak (uV)'});
    FC5tab=table(FC5index, FC5pk, 'VariableNames', {'FC5 Index (s)', 'FC5 Peak (uV)'});
    T7tab=table(T7index, T7pk, 'VariableNames', {'T7 Index (s)', 'T7 Peak (uV)'});
    P7tab=table(P7index, P7pk, 'VariableNames', {'P7 Index (s)', 'P7 Peak (uV)'});
    O1tab=table(O1index, O1pk, 'VariableNames', {'O1 Index (s)', 'O1 Peak (uV)'});
    O2tab=table(O2index, O2pk, 'VariableNames', {'O2 Index (s)', 'O2 Peak (uV)'});
    P8tab=table(P8index, P8pk, 'VariableNames', {'P8 Index (s)', 'P8 Peak (uV)'});
    T8tab=table(T8index, T8pk, 'VariableNames', {'T8 Index (s)', 'T8 Peak (uV)'});
    FC6tab=table(FC6index, FC6pk, 'VariableNames', {'FC6 Index (s)', 'FC6 Peak (uV)'});
    F4tab=table(F4index, F4pk, 'VariableNames', {'F4 Index (s)', 'F4 Peak (uV)'});
    F8tab=table(F8index, F8pk, 'VariableNames', {'F8 Index (s)', 'F8 Peak (uV)'});
    AF4tab=table(AF4index, AF4pk, 'VariableNames', {'AF4 Index (s)', 'AF4 Peak (uV)'});
    pkpm="Minimum peak prominence is " + mnpkprom;
    %Exports peak data to excel document - single sheet (Name: Try 4 Peaks
    %and Indices)
    filename = 'Try 4 Peaks and Indices.xlsx';
    writematrix(pkpm, filename,'Sheet',1,'Range','A1');
    writetable(AF3tab,filename,'Sheet',1,'Range','A2');
    writetable(F7tab, filename, 'Sheet',1, 'Range', 'C2');
    writetable(F3tab, filename, 'Sheet',1, 'Range', 'E2');
    writetable(FC5tab, filename, 'Sheet',1, 'Range', 'G2');
    writetable(T7tab, filename, 'Sheet',1, 'Range', 'I2');
    writetable(P7tab, filename, 'Sheet',1, 'Range', 'K2');
    writetable(O1tab, filename, 'Sheet',1, 'Range', 'M2');
    writetable(O2tab, filename, 'Sheet',1, 'Range', 'O2');
    writetable(P8tab, filename, 'Sheet',1, 'Range', 'Q2');
    writetable(T8tab, filename, 'Sheet',1, 'Range', 'S2');
    writetable(FC6tab, filename, 'Sheet',1, 'Range', 'U2');
    writetable(F4tab, filename, 'Sheet',1, 'Range', 'W2');
    writetable(F8tab, filename, 'Sheet',1, 'Range', 'Y2');
    writetable(AF4tab, filename, 'Sheet',1, 'Range', 'AA2');

I also attached the full matlab code I am using in the zip file, along with the files you need to run the code.

Thank You!

EDIT/ADDED:

Below is an image of what I'm trying to get. I want the data in an excel file as a table. I will add the subject # every time, but I want to automate everything else in the table, since I have 15 datasets of about 20 mins length each to go through.

Answer 1

[Kevin Holly]

% Importing_and_Plotting_EEG_Example
close all; clear all; clc;
format long;
% Importing csv data
T=readtable('Try 4.csv'); %This reads the csv data into a table named T
timestampOrig=T.Timestamp; %this makes timestampOrig equal to the original Timestamp
T.Timestamp=T.Timestamp-T.Timestamp(1); %This changes the official Timestamp column so it is 0 at the start of the recording
% Changes the sensor names from EEG_<sensor> to <sensor>
T.Properties.VariableNames(2:end)=extractAfter(T.Properties.VariableNames(2:end),'_');
%T5=head(T, 5) %shows first 5 rows of table T
Int=readtable('Event Marker Try 4_EPOCX_126368_2021.06.04T15.42.31.04.00_intervalMarker.csv');
EventTime=Int.latency;
EventMarkerLabel=Int.type;
EvtLab=readtable('Try 4 Event Labels.xlsx');
EvtLab{2,2} = {'Blink Eye'};
table(EvtLab)

% Preallocate variable
Event_Labels = cell(length(EventTime),1);

% Identify Event Labels
for i = 1:size(EvtLab,1)
    Event_Labels(contains(EventMarkerLabel(1:length(EventTime)),EvtLab{i,2},'IgnoreCase',true),1) = EvtLab{i,1};
end

Plots all together

p=plot(T.Timestamp,T{:,2:width(T)});
xline(EventTime,'--',Event_Labels);


% Preallocate variables
Firstpeakafterevent = zeros([width(T), size(EventTime)]);
timeoffirstpeakafterevent = zeros([width(T), size(EventTime)]);
timefromeventtofirstpeak = zeros([width(T), size(EventTime)]);

% Plot
for i=2:width(T)
    [pks,locs] = findpeaks(T{:,i},T.Timestamp, 'MinPeakProminence', 100);

    for ii = 1:length(EventTime)
        index = find(locs>EventTime(ii),1);
        if ~isempty(index)
            Firstpeakafterevent(i-1,ii,:) = pks(index);
            timeoffirstpeakafterevent(i-1,ii,:) = locs(index);
            timefromeventtofirstpeak(i-1,ii,:) = locs(index)-EventTime(ii);%time from event to first peak
        end
    end

    x =  timeoffirstpeakafterevent(i-1,:);
    y =  Firstpeakafterevent(i-1,:);
    x(x==0) = [];
    y(y==0) = [];

    hold on
    scatter(x,y,'v','filled','MarkerFaceColor',p(i-1).Color)
end

legend(p,T.Properties.VariableNames(2:width(T)))

If you want separate figures

for i=2:width(T)
    [pks,locs] = findpeaks(T{:,i},T.Timestamp, 'MinPeakProminence', 100);

    for ii = 1:length(EventTime)
        index = find(locs>EventTime(ii),1);
        if ~isempty(index)
            Firstpeakafterevent(i-1,ii,:) = pks(index);
            timeoffirstpeakafterevent(i-1,ii,:) = locs(index);
            timefromeventtofirstpeak(i-1,ii,:) = locs(index)-EventTime(ii);%time from event to first peak
        end
    end

    x =  timeoffirstpeakafterevent(i-1,:);
    y =  Firstpeakafterevent(i-1,:);
    x(x==0) = [];
    y(y==0) = [];

    figure(i-1)
    plot(T.Timestamp,T{:,i})
    hold on
    scatter(x,y,'v','filled')
    xline(EventTime,'--',Event_Labels);
   ylabel(T.Properties.VariableNames(i))
end

[Christina Diersing]

Actually, I was trying to get an excel file/table like the one below. I can add the subject number, but I'm trying to get the rest of the table with an automated process, since I have to go through 15 datasets of about 20 minutes each.

[Christina Diersing]

I also want it to say something like N/A or 0 if there isn't a peak in that section

[Kevin Holly]

You can create a table of the data as such:

timefromeventtofirstpeak = timefromeventtofirstpeak'; %transposing data so it fits table
timeoffirstpeakafterevent = timeoffirstpeakafterevent';
Firstpeakafterevent = Firstpeakafterevent';

t=table
t.EventLabels = Event_Labels
t.Latency = timefromeventtofirstpeak(:,1);% you can change 1 into a variable in used for a for loop
t.Time_of_Peak = timeoffirstpeakafterevent(:,1);
t.PeakHeight = Firstpeakafterevent;

You can save this in Excel using the writetable function. You could create a for loop to create a table for each electrode channel. You could either combine the tables or save each table on a separate Excel sheet.

[Christina Diersing]

Thank You!

FirstPeakAfterEvent is a 11x15 matrix. However, the last column contains only zeros. Are the 15 columns for the electrodes (if so, how do I get rid of the last column, which I assume is spare since there are only 14 electrodes)? I am trying to at least label the electrodes using the following code, but it keeps coming up with an error. I think this is due to the extra column.

%% Data Table
timefromeventtofirstpeak = timefromeventtofirstpeak'; %transposing data so it fits table
timeoffirstpeakafterevent = timeoffirstpeakafterevent';
Firstpeakafterevent = Firstpeakafterevent';
filename='Try 4 Event to Peak Times and Amplitudes.xlsx';
pkHeighttab=table(Firstpeakafterevent, 'VariableNames',{'AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'});
t=table
t.EventLabels = Event_Labels
t.Latency = timefromeventtofirstpeak(:,1);% you can change 1 into a variable in used for a for loop
t.Time_of_Peak = timeoffirstpeakafterevent(:,1);
%t.PeakHeight = Firstpeakafterevent;
t.PeakHeight=pkHeighttab;
%t.pkHeighttab
writetable(t,filename,'Sheet',1,'Range','A1');

[Kevin Holly]

I preallocated the variables incorrectly.

It should be "width(T)-1" instead of "width(T)" since I started the for loop at 2 instead of 1 because I believe the first column was header information.

Firstpeakafterevent = zeros([width(T)-1, size(EventTime)]);
timeoffirstpeakafterevent = zeros([width(T)-1, size(EventTime)]);
timefromeventtofirstpeak = zeros([width(T)-1, size(EventTime)]);

[Christina Diersing]

Thank you!

And I made those changes, but I am still having trouble labelling the peak height columns. This is the error I keep getting:

Error using table (line 344)
The VariableNames property must contain one name for each variable in the table.

Error in Event_to_First_Peak_Try_4 (line 68)
pkHeighttab=table(Firstpeakafterevent, 'VariableNames',{'AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'});

From the following code segment

filename='Try 4 Event to Peak Times and Amplitudes.xlsx';
pkHeighttab=table(Firstpeakafterevent, 'VariableNames',{'AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'});
t=table
t.EventLabels = Event_Labels
t.Latency = timefromeventtofirstpeak(:,1);% you can change 1 into a variable in used for a for loop
t.Time_of_Peak = timeoffirstpeakafterevent(:,1);
%t.PeakHeight = Firstpeakafterevent;
t.PeakHeight=pkHeighttab;
%t.pkHeighttab
writetable(t,filename,'Sheet',1,'Range','A1');

I really appreciate your help!

[Kevin Holly]

check the size of Firstpeakafterevent

size(Firstpeakafterevent)

Does the amount of variable names match the columns? The output of the command aboves gives the numbers of rows then the number of columns.

You may need to place that command before it was transposed.

pkHeighttab=table(Firstpeakafterevent, 'VariableNames',{'AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'});
Firstpeakafterevent = Firstpeakafterevent';

Why are you trying to create this new table?

[Christina Diersing]

I tried it both ways - same error comes up. When I had the pkHeighttab before transposing the Firstpeakafterevent, size(Firstpeakafterevent) resulted in 14 11. When I have pkHeighttab after transposing Firstpeakafterevent, the size command results in 11 14 (I think this is what I need to match the pkHeighttab).

I have counted the 'VariableNames' and there are 14, 1 per electrode. I have checked the VariableNames for missed apostrophes or commas and I haven't found any missing.

I am only making the new table so I can add the column headers to the table. It's just the simplest way I know how to do this. Do you have a better way/another way to add the electrode labels to the data table?

[Kevin Holly]

The way you created the table, it placed the double array under one column.

Firstpeakafterevent=rand(11,14);
pkHeighttab=table(Firstpeakafterevent)

pkHeighttab = 11×1 table
    Firstpeakafterevent
    ___________________

        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    
        1×14 double    

You would need to separate each column by a comma as such:

pkHeighttab=table(Firstpeakafterevent(:,1),Firstpeakafterevent(:,2),Firstpeakafterevent(:,3))

pkHeighttab = 11×3 table
      Var1        Var2       Var3  
    ________    ________    _______

     0.91548     0.53932    0.15695
      0.3958     0.94602    0.88045
     0.72436    0.012954    0.12307
     0.02383     0.83487    0.49804
     0.45529     0.28293    0.92919
     0.98902     0.04194    0.74863
    0.062716     0.98443    0.84267
     0.84436     0.44308    0.72737
     0.51626     0.41849    0.56984
     0.81102     0.66133    0.66442
     0.46538     0.34246    0.47693

Or you could convert the double array to a table

pkHeighttab = array2table(Firstpeakafterevent)

pkHeighttab = 11×14 table
    Firstpeakafterevent1    Firstpeakafterevent2    Firstpeakafterevent3    Firstpeakafterevent4    Firstpeakafterevent5    Firstpeakafterevent6    Firstpeakafterevent7    Firstpeakafterevent8    Firstpeakafterevent9    Firstpeakafterevent10    Firstpeakafterevent11    Firstpeakafterevent12    Firstpeakafterevent13    Firstpeakafterevent14
    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    _____________________    _____________________    _____________________    _____________________    _____________________

           0.91548                 0.53932                0.15695                   0.2983                0.43321                  0.25706                 0.95719                0.46169                  0.78282                 0.55814                  0.43405                  0.25589                  0.98482                  0.71497       
            0.3958                 0.94602                0.88045                  0.72518                0.63816                  0.33298                 0.69865                0.20153                  0.96136                0.090752                 0.055538                  0.23726                  0.18578                  0.18681       
           0.72436                0.012954                0.12307                  0.32115                0.75753                  0.32891                0.080961                0.23991                  0.86445                 0.70328                  0.13634                   0.6909                  0.84343                  0.41134       
           0.02383                 0.83487                0.49804                  0.97391                0.85306                  0.85585                 0.41278                0.22424                  0.76531                 0.23502                  0.63367                  0.51952                  0.39837                  0.32099       
           0.45529                 0.28293                0.92919                  0.64402                0.81809                 0.050335                 0.59443                0.53354                  0.28266                  0.2321                  0.97612                  0.95146                 0.011157                  0.83921       
           0.98902                 0.04194                0.74863                 0.053351                0.48814                  0.49267                 0.35014                 0.3223                  0.14861                 0.96482                  0.22227                  0.27073                  0.92724                  0.71481       
          0.062716                 0.98443                0.84267                  0.26928                0.27327                  0.10274                 0.48143                0.17495                  0.99477                 0.15691                  0.29287                 0.038963                 0.072009                  0.39512       
           0.84436                 0.44308                0.72737                  0.18656                0.35959                  0.69748                 0.81745                0.18534                 0.068229                0.039915                  0.59896                  0.96391                  0.38926                  0.84925       
           0.51626                 0.41849                0.56984                   0.5134                0.29875                  0.83267                0.099013                0.68609                  0.83722                  0.3321                  0.67596                 0.021001                  0.46273                   0.2664       
           0.81102                 0.66133                0.66442                  0.39368                0.13166                  0.27145                 0.13774                0.66161                  0.89902                 0.57047                  0.79547                  0.25839                  0.78042                  0.86882       
           0.46538                 0.34246                0.47693                  0.18449                0.78324                  0.84633                 0.16619                0.98957                  0.31728                 0.47823                  0.23677                  0.54935                  0.83233                  0.99389       

pkHeighttab.Properties.VariableNames = {'AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'}

pkHeighttab = 11×14 table
     AF3 Pk      F7 Pk       F3 Pk      FC5 Pk      T7 Pk      P7 Pk       O1 Pk       O2 Pk      P8 Pk       T8 Pk       FC6 Pk      F4 Pk       F8 Pk      AF4 Pk 
    ________    ________    _______    ________    _______    ________    ________    _______    ________    ________    ________    ________    ________    _______

     0.91548     0.53932    0.15695      0.2983    0.43321     0.25706     0.95719    0.46169     0.78282     0.55814     0.43405     0.25589     0.98482    0.71497
      0.3958     0.94602    0.88045     0.72518    0.63816     0.33298     0.69865    0.20153     0.96136    0.090752    0.055538     0.23726     0.18578    0.18681
     0.72436    0.012954    0.12307     0.32115    0.75753     0.32891    0.080961    0.23991     0.86445     0.70328     0.13634      0.6909     0.84343    0.41134
     0.02383     0.83487    0.49804     0.97391    0.85306     0.85585     0.41278    0.22424     0.76531     0.23502     0.63367     0.51952     0.39837    0.32099
     0.45529     0.28293    0.92919     0.64402    0.81809    0.050335     0.59443    0.53354     0.28266      0.2321     0.97612     0.95146    0.011157    0.83921
     0.98902     0.04194    0.74863    0.053351    0.48814     0.49267     0.35014     0.3223     0.14861     0.96482     0.22227     0.27073     0.92724    0.71481
    0.062716     0.98443    0.84267     0.26928    0.27327     0.10274     0.48143    0.17495     0.99477     0.15691     0.29287    0.038963    0.072009    0.39512
     0.84436     0.44308    0.72737     0.18656    0.35959     0.69748     0.81745    0.18534    0.068229    0.039915     0.59896     0.96391     0.38926    0.84925
     0.51626     0.41849    0.56984      0.5134    0.29875     0.83267    0.099013    0.68609     0.83722      0.3321     0.67596    0.021001     0.46273     0.2664
     0.81102     0.66133    0.66442     0.39368    0.13166     0.27145     0.13774    0.66161     0.89902     0.57047     0.79547     0.25839     0.78042    0.86882
     0.46538     0.34246    0.47693     0.18449    0.78324     0.84633     0.16619    0.98957     0.31728     0.47823     0.23677     0.54935     0.83233    0.99389

[Kevin Holly]

For the electrodes, I was envisioning that you would use a for loop to create a table for each electrode, where each table would be saved to its own sheet. Where the electrode label would be saved in cell 'B4' and on the sheet name itself for instance.

Something like this:

filename = 'test.xlsx';
Electrodes = {'AF3','F7','F3','FC5','T7','P7','O1','O2','P8','T8','FC6','F4','F8','AF4'};
for i=1:14
    %insert code to generate table%
    writetable(t,filename,'Sheet',Electrodes{i},'Range','A5');
    writematrix("Electrodes",filename,'Sheet',Electrodes{i},'Range','A4')
    writematrix(Electrodes{i},filename,'Sheet',Electrodes{i},'Range','B4')
    writematrix("Subject #",filename,'Sheet',Electrodes{i},'Range','A4')
end

[Christina Diersing]

Originally that is how I thought I wanted it set up, but I like the current set up better. Again, thank you so much for your help!

For anyone looking at this later, this is the complete example code I used:

%% Event_to_First_Peak_Try_4
close all; clear all; clc;
% add folder with csv file to path
addpath 'C:\Users\chris\Documents\College\Sixth Year\DAGSI\Data\EMOTIV Recordings\Event Marker Try 4'
% change current directory to where this Matlab file is
cd 'C:\Users\chris\Documents\College\Sixth Year\DAGSI\Data\EMOTIV Recordings'
format long;
% Importing csv data
T=readtable('Try 4.csv'); %This reads the csv data into a table named T
timestampOrig=T.Timestamp; %this makes timestampOrig equal to the original Timestamp
T.Timestamp=T.Timestamp-T.Timestamp(1); %This changes the official Timestamp column so it is 0 at the start of the recording
% Changes the sensor names from EEG_<sensor> to <sensor>
T.Properties.VariableNames(2:end)=extractAfter(T.Properties.VariableNames(2:end),'_');
%T5=head(T, 5) %shows first 5 rows of table T
Int=readtable('Event Marker Try 4_EPOCX_126368_2021.06.04T15.42.31.04.00_intervalMarker.csv');
EventTime=Int.latency; %Imports the latency from the file
EventMarkerLabel=Int.type; %Imports the event type/label from the file
% EvtLab=readtable('Try 4 Event Labels.xlsx'); %Import event markers and abbreviations used for plot
% %EvtLab{2,2} = {'Blink Eye'};
% table(EvtLab) %View legend (in table form) of abbreviations used in the plot

% Preallocate variable
Event_Labels = cell(length(EventTime),1);
%Event Labels
Event_Labels=EventMarkerLabel;

%% Plots all together
%creates plot
p=plot(T.Timestamp,T{:,2:width(T)});
xline(EventTime,'--',Event_Labels);%creates vertical lines marking events

% Preallocate variables
Firstpeakafterevent = zeros([width(T)-1, size(EventTime)]);
timeoffirstpeakafterevent = zeros([width(T)-1, size(EventTime)]);
timefromeventtofirstpeak = zeros([width(T)-1, size(EventTime)]);

% Plot
for i=2:width(T) %for the EEG electrode data
    %find peaks and locations/times of peaks
    [pks,locs] = findpeaks(T{:,i},T.Timestamp, 'MinPeakProminence', 100);

    for ii = 1:length(EventTime) %for the experiment length
        index = find(locs>EventTime(ii),1); %finds the location(peak) after the event, but closest to the event
        if ~isempty(index)
            Firstpeakafterevent(i-1,ii,:) = pks(index); %stores peak values in array Firstpeakafterevent
            timeoffirstpeakafterevent(i-1,ii,:) = locs(index); %Stores peak times in the array timeoffirstpeakafterevent
            timefromeventtofirstpeak(i-1,ii,:) = locs(index)-EventTime(ii);%time from event to first peak
        end
    end

    x =  timeoffirstpeakafterevent(i-1,:);
    y =  Firstpeakafterevent(i-1,:);
    x(x==0) = [];
    y(y==0) = [];

    hold on
    scatter(x,y,'v','filled','MarkerFaceColor',p(i-1).Color) %Creates scatterplot for the first peak after each event
end
grid on;
legend(p,T.Properties.VariableNames(2:width(T))) %view legend
%% Data Table
%transposing data so it fits table
timefromeventtofirstpeak = timefromeventtofirstpeak'; 
timeoffirstpeakafterevent = timeoffirstpeakafterevent';
Firstpeakafterevent = Firstpeakafterevent';
%Filename to print table to
filename='Try 4 Event to Peak Times and Amplitudes.xlsx';
%Create table t with event labels, latency, time of peak, and peak
%amplitudes
t=table(Event_Labels, timefromeventtofirstpeak(:,1), timeoffirstpeakafterevent(:,1), Firstpeakafterevent(:,1),Firstpeakafterevent(:,2),Firstpeakafterevent(:,3),Firstpeakafterevent(:,4),Firstpeakafterevent(:,5),Firstpeakafterevent(:,6),Firstpeakafterevent(:,7),Firstpeakafterevent(:,8),Firstpeakafterevent(:,9),Firstpeakafterevent(:,10),Firstpeakafterevent(:,11),Firstpeakafterevent(:,12),Firstpeakafterevent(:,13),Firstpeakafterevent(:,14));
%Label columns
t.Properties.VariableNames = {'Event','Latency after Event','Time of Peak','AF3 Pk','F7 Pk','F3 Pk','FC5 Pk','T7 Pk','P7 Pk','O1 Pk','O2 Pk','P8 Pk','T8 Pk','FC6 Pk','F4 Pk','F8 Pk','AF4 Pk'};
%Write to excel file
writetable(t,filename,'Sheet',1,'Range','A1');