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	All of these code samples currently are mis-identified in my repositories. I'm donating them to the cause.
		
			
				
	
	
		
			60 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Matlab
		
	
	
	
	
	
			
		
		
	
	
			60 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Matlab
		
	
	
	
	
	
| function [ x_T, y_T, vx_T, e_T, filter, delta_e ] = Integrate_FTLE_Gawlick_ell( x_0, y_0, vx_0, e_0, T, mu, ecc, nu, options)
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| %Integrate
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| %   This function performs Runge-Kutta-Fehlberg integration for given
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| %   initial conditions to compute FTLE to obtain the image in the Gawlick's
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| %   article "Lagrangian Coherent Structures in the Elliptic Restricted
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| %   Three-Body Problem".
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| nx=length(x_0);
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| ny=length(y_0);
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| nvx=length(vx_0);
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| ne=length(e_0);
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| vy_0=zeros(nx,ny,nvx,ne);
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| x_T=zeros(nx,ny,nvx,ne);
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| y_T=zeros(nx,ny,nvx,ne);
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| vx_T=zeros(nx,ny,nvx,ne);
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| vy_T=zeros(nx,ny,nvx,ne);
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| e_T=zeros(nx,ny,nvx,ne);
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| delta_e=zeros(nx,ny,nvx,ne);
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| %% Look for phisically meaningful points
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| filter=zeros(nx,ny,nvx,ne);  %0=meaningless point 1=meaningful point
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| useful=ones(nx,ny,nvx,ne);
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| %% Integrate only useful points
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| useful(:,1,:,1)=0;
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| useful(:,1,:,3)=0;
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| useful(:,3,:,1)=0;
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| useful(:,3,:,3)=0;
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| 
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| %% Integrate only meaningful points
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| h=waitbar(0,'','Name','Integration in progress, please wait!');
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| for i=1:nx
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| 	waitbar(i/nx,h,sprintf('Computing i=%i',i));
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| 	for j=1:ny
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| 		parfor k=1:nvx
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| 			for l=1:ne
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| 				if useful(i,j,k,l)
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| 					vy_0(i,j,k,l)=-sqrt(2*(Omega(x_0(i),y_0(j),mu)/(1+ecc*cos(nu)))+2*e_0(l)-vx_0(k)^2);
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| 					if isreal(vy_0(i,j,k,l))
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| 						filter(i,j,k,l)=1;
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| 						
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| 						ci=[x_0(i), y_0(j), vx_0(k), vy_0(i,j,k,l)];
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| 						[t,Y]=ode45(@f_ell,[0 T], ci, options, mu, ecc);
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| 						
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| 						if abs(t(end)) < abs(T) % Consider also negative time
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| 							filter(i,j,k,l)=3
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| 						end
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| 						
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| 						x_T(i,j,k,l)=Y(end,1);
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| 						y_T(i,j,k,l)=Y(end,2);
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| 						vx_T(i,j,k,l)=Y(end,3);
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| 						vy_T(i,j,k,l)=Y(end,4);
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| 						e_T(i,j,k,l)=0.5*(vx_T(i,j,k,l)^2+vy_T(i,j,k,l)^2)-Omega(x_T(i,j,k,l),y_T(i,j,k,l),mu);
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| 						
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| 						% Compute the goodness of the integration
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| 						delta_e(i,j,k,l)=abs(e_T(i,j,k,l)-e_0(l));
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| 					end
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| 				end
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| 			end
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| 		end
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| 	end
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| end
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| close(h); |