hello
try this... hope it helps - though I did not draw vertical lines but you have to start and ending points coordinates.
I tested the code on the 10 examples data provided
load('example_data.mat')
% whos
% Name Size Bytes Class Attributes
%
% example1 1096x1 8768 double
% example10 486x1 3888 double
% example2 1327x1 10616 double
% example3 1116x1 8928 double
% example4 690x1 5520 double
% example5 642x1 5136 double
% example6 720x1 5760 double
% example7 834x1 6672 double
% example8 655x1 5240 double
% example9 790x1 6320 double
data = example1;
% high pass filter the data first
[b,a] = butter(2,0.01,'high');
datad = filtfilt(b,a,data);
% find start , end points = positive and negative peaks of the high pass
% filtered data (with islocalmax)
minpeakdist = 50;
min_amplitude= max(abs(datad))/10;
tf=islocalmax(datad,'MinSeparation',minpeakdist, 'MinProminence', 1);
locsp = find(tf);
locsp = locsp(datad(locsp)>min_amplitude);
tf=islocalmax(-datad,'MinSeparation',minpeakdist, 'MinProminence', 1);
locsn = find(tf);
locsn = locsn(datad(locsn)<-min_amplitude);
locsn(locsn>locsp(end)) = []; % remove "start" point wich is now followed by "end" point at the end of the data
% plot
xaxis = 1:numel(data);
% plot(xaxis,datad,xaxis(locsn),datad(locsn),'dk',xaxis(locsp),datad(locsp),'dr');
plot(xaxis,data,xaxis(locsn),data(locsn),'dk',xaxis(locsp),data(locsp),'dr');
legend('data','start points','end points','Location','NorthEastOutside');
