Coherent Backscattering from Multiple Scattering Systems - KOPS ...

MATLAB codes
% reference files
index = regexp (name_ref, ’_’, ’start’) ;
index = index (length(index) - 1) ;
namebase = name_ref (1 : index) ;
list = dir ([path_ref,namebase,’*.dat’]) ;
data_ref = zeros (size(list,1),256,2) ;
P_ref = zeros (size(list,1),1) ;
for N = 1 : size(list,1)
filename = [path,list(N).name] ;
data_ref(N,:,:) = load (filename,’-ascii’) ;
parts = regexp (list(N).name, ’_|+-|.dat’, ’split’) ;
p_ref = parts ( size(parts,2) - 2 ) ;
P_ref(N) = str2double (p_ref:,1) ;
end
% other data
k = 2 * pi / wavelength ;
c = 3e8 ; % speed of light
l_approx = D * n_eff / c ;
n_surr = 1 ; % refractive index of surrounding medium = air
R = reflectivity (n_eff,n_surr) ;
%% Calibrate data
cone = zeros(256,1) ;
cone_delta = zeros(256,1) ;
for n = 1 : 256
x = data_ref(:,n) ;
y = P_ref * diffuson(theta(n),l_approx,R) ;
temp1 = sortrows ([x,y],1) ; % sort by x
x = temp1(:,1) ;
y = temp1(:,2) ;
warning off % many warnings because of defect photodiodes (causing NANs)!
[p,s,mu] = polyfit (x,y,3) ;
[cone(n),cone_delta(n)] = polyval (p,data_samp(n),s,mu) ;
warning on
end
%% Fold data
dummy = sortrows ([abs(theta), cone, cone_delta]) ;
theta = dummy (:,1) ;
cone = dummy (:,2) ;
cone_delta = dummy (:,3) ;
82