OK, this seems to to work. The x-y coordinates of the marked points are output to the command window (along with the figure number). For brevity, I'm just showing the result for the 1st data set.
format shortg
xlsdata=xlsread('temp.xlsx'); % this is the data in your ForDataMining.xlsx file
Wavelength=xlsdata(2:2152);
for i=1:1 % first data set only, adjust as desired
reflection = xlsdata(2:2152,i+1);
lmin = islocalmin(reflection,"MinProminence",0.01,"MinSeparation",100);
% get x-y coordinates of minima
x = Wavelength(lmin)';
y = reflection(lmin);
figNumber = repmat(i, numel(x), 1);
[figNumber x y] % output in command window (include figure number)
figure(i) % put figure statement here
plot(Wavelength,reflection,Wavelength(lmin),reflection(lmin),'ro')
title('Relative Reflectance-Wavelength')
xlabel('Wavelength[nm]')
ylabel('Relative Reflectance')
grid on
grid minor
end
