%% Filter one particular signal
A=M12(:,2);%% Signal you want to filter
WA = M1(:,1); %% Wavelengths of the signal you want to filter.
 
nm = 100;
coeff = ones(1, nm)/nm;
fDelay = (length(coeff)-1)/2;
 
 
avg = filter(coeff, 1, -A(:,1));
 
figure
hold all
xlim ([1526 1624])
plot(WA/1e-9,-A(:,1));
plot(WA/1e-9-.0015,avg,'LineWidth',2);
title('SiWG023-C3: GC4, 19 degrees, 2000um, c');
    xlabel('Wavelength (nm)');
    ylabel('Loss (dB/mm)');
    legend('Measurmenet','"Actual" transmission');
    grid minor