CLEANUP - changes to folder structure

Theory/Optical/calcFWM/analytical_calculation_paper.m

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+%%FWM analysis from "Analytical Calculation of the Number of
+%%Four-Wave-Mixing Products in Optical Multichannel Communication Systems"
+
+N_ = [4,8,16];
+
+df_hz = 400e9;
+center_nm = 1310;
+
+figure()
+for i = 1:length(N_)
+
+    vec = (2*N_(i)-1:-1:2-N_(i)) -(N_(i)/2+0.5);
+    channelplan_hz = nm2hz(center_nm) + (vec * df_hz) ;
+    channelplan_nm = hz2nm(channelplan_hz);
+
+    [Mndg,Mdg] = getProducts(N_(i));
+    total(i) = sum(Mndg) + sum(Mdg);
+    subplot(1,length(N_),i)
+    xline(calcWavelengthPlan(N_(i), df_hz, center_nm));
+    hold on
+    stem(channelplan_nm,(Mndg+Mdg),'filled','LineWidth',1,'Marker','o','MarkerSize',2)
+    stem(channelplan_nm,(Mdg),'filled','LineWidth',1,'Marker','none');
+    ylim([0,100])
+    xlim([1260, 1365]);
+    grid off
+    xlabel('O-band wavelength region in nm');
+    ylabel('Number of FWM products');
+    title([num2str(N_(i)),' ch.'])
+
+end
+
+
+function [Mndg,Mdg] = getProducts(N)
+ 
+    s = abs(2-N-1) ;
+    
+    for n = 2-N:2*N-1  
+    
+        if n<-N
+            Mdg(n+s) = 0;
+        elseif (-N <= n)&&(n <= 0)
+            Mdg(n+s) = N - ceil((N-n)/2);
+        elseif (1 <= n)&&(n <= N)
+            Mdg(n+s) = N - 1 - floor(n/2) - ceil((N-n)/2);
+        elseif (N < n)&&(n <= 2*N)
+            Mdg(n+s) = N - floor(n/2);
+        elseif n > 2*N
+            Mdg(n+s) = 0;
+        end
+    
+        if n<-N
+            Mndg(n+s) = 0;
+        elseif (-N <= n)&&(n < 1)
+            Mndg(n+s) = ceil((N^2 + n^2 - 2*N - 2*n + 2*N*n)/4);
+        elseif (1 <= n)&&(n <= N)
+            Mndg(n+s) = ceil(((N^2 - 6*N - 2*n^2 + 2*n + 4)/4) + floor((N*n)/2));
+        elseif (N < n)&&(n <= 2*N)
+            Mndg(n+s) = floor(N^2 + n^2 /4 - N*n);
+        elseif n > 2*N
+            Mndg(n+s) = 0;
+        end
+    
+    end
+end
+