Added matlab code samples.

All of these code samples currently are mis-identified in my repositories. I'm
donating them to the cause.
This commit is contained in:
Michele Mastropietro
2013-02-22 10:57:51 +01:00
parent b45c4f5379
commit c85255c5af
14 changed files with 803 additions and 0 deletions

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x_0=linspace(0,100,101);
vx_0=linspace(0,100,101);
z=zeros(101,101);
for i=1:101
for j=1:101
z(i,j)=x_0(i)*vx_0(j);
end
end
figure
pcolor(x_0,vx_0,z)
shading flat

149
samples/Matlab/FTLEH.m Normal file
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tic
clear all
%% Choice of the mass parameter
mu=0.1;
%% Computation of Lagrangian Points
[xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5] = Lagr(mu);
%% Computation of initial total energy
E_L1=-Omega(xl1,yl1,mu);
E=E_L1+0.03715; % Offset as in figure 2.2 "LCS in the ER3BP"
%% Initial conditions range
x_0_min=-0.8;
x_0_max=-0.2;
vx_0_min=-2;
vx_0_max=2;
y_0=0;
% Elements for grid definition
n=200;
% Dimensionless integrating time
T=2;
% Grid initializing
[x_0,vx_0]=ndgrid(linspace(x_0_min,x_0_max,n),linspace(vx_0_min,vx_0_max,n));
vy_0=sqrt(2*E+2*Omega(x_0,y_0,mu)-vx_0.^2);
% Kinetic energy computation
E_cin=E+Omega(x_0,y_0,mu);
%% Transforming into Hamiltonian variables
px_0=vx_0-y_0;
py_0=vy_0+x_0;
% Inizializing
x_T=zeros(n,n);
y_T=zeros(n,n);
px_T=zeros(n,n);
py_T=zeros(n,n);
filtro=ones(n,n);
E_T=zeros(n,n);
a=zeros(n,n); % matrix of numbers of integration steps for each integration
np=0; % number of integrated points
fprintf(' con n = %i\n',n)
%% Energy tolerance setting
energy_tol=inf;
%% Computation of the Jacobian of the system
options=odeset('Jacobian',@cr3bp_jac);
%% Parallel integration of equations of motion
parfor i=1:n
for j=1:n
if E_cin(i,j)>0 && isreal(vy_0(i,j)) % Check for real velocity and positive Kinetic energy
[t,Y]=ode45(@fH,[0 T],[x_0(i,j); y_0; px_0(i,j); py_0(i,j)],options);
% Try to obtain the name of the solver for a following use
% sol=ode45(@f,[0 T],[x_0(i,j); y_0; vx_0(i,j); vy_0(i,j)],options);
% Y=sol.y';
% solver=sol.solver;
a(i,j)=length(Y);
%Saving solutions
x_T(i,j)=Y(a(i,j),1);
px_T(i,j)=Y(a(i,j),3);
y_T(i,j)=Y(a(i,j),2);
py_T(i,j)=Y(a(i,j),4);
%Computation of final total energy and difference with
%initial one
E_T(i,j)=EnergyH(x_T(i,j),y_T(i,j),px_T(i,j),py_T(i,j),mu);
delta_E=abs(E_T(i,j)-E);
if delta_E > energy_tol; %Check of total energy conservation
fprintf(' Ouch! Wrong Integration: i,j=(%i,%i)\n E_T=%.2f \n delta_E=%.2f\n\n',i,j,E_T(i,j),delta_E);
filtro(i,j)=2; %Saving position of the point
end
np=np+1;
else
filtro(i,j)=0; % 1=interesting point; 0=non-sense point; 2= bad integration point
end
end
end
t_integrazione=toc;
fprintf(' n = %i\n',n)
fprintf(' energy_tol = %.2f\n',energy_tol)
fprintf('total \t%i\n',n^2)
fprintf('nunber \t%i\n',np)
fprintf('time to integrate \t%.2f s\n',t_integr)
%% Back to Lagrangian variables
vx_T=px_T+y_T;
vy_T=py_T-x_T;
%% FTLE Computation
fprintf('adesso calcolo ftle\n')
tic
dphi=zeros(2,2);
ftle=zeros(n-2,n-2);
for i=2:n-1
for j=2:n-1
if filtro(i,j) && ... % Check for interesting point
filtro(i,j-1) && ...
filtro(i,j+1) && ...
filtro(i-1,j) && ...
filtro(i+1,j)
dphi(1,1)=(x_T(i-1,j)-x_T(i+1,j))/(x_0(i-1,j)-x_0(i+1,j));
dphi(1,2)=(x_T(i,j-1)-x_T(i,j+1))/(vx_0(i,j-1)-vx_0(i,j+1));
dphi(2,1)=(vx_T(i-1,j)-vx_T(i+1,j))/(x_0(i-1,j)-x_0(i+1,j));
dphi(2,2)=(vx_T(i,j-1)-vx_T(i,j+1))/(vx_0(i,j-1)-vx_0(i,j+1));
if filtro(i,j)==2 % Manual setting to visualize bad integrated points
ftle(i-1,j-1)=-Inf;
else
ftle(i-1,j-1)=1/(2*T)*log(max(abs(eig(dphi'*dphi))));
end
end
end
end
%% Plotting results
% figure
% plot(t,Y)
% figure
% plot(Y(:,1),Y(:,2))
% figure
xx=linspace(x_0_min,x_0_max,n);
vvx=linspace(vx_0_min,vx_0_max,n);
[x,vx]=ndgrid(xx(2:n-1),vvx(2:n-1));
figure
pcolor(x,vx,ftle)
shading flat
t_ftle=toc;
fprintf('tempo per integrare \t%.2f s\n',t_integrazione)
fprintf('tempo per calcolare ftle \t%.2f s\n',t_ftle)
% save(['var_' num2str(n) '_' num2str(clock(4)])
nome=['var_xvx_', 'ode00', '_n',num2str(n),'_e',num2str(energy_tol),'_H'];
save(nome)

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samples/Matlab/FTLE_reg.m Normal file
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tic
clear all
%% Elements for grid definition
n=100;
%% Dimensionless integrating time
T=2;
%% Choice of the mass parameter
mu=0.1;
%% Computation of Lagrangian Points
[xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5] = Lagr(mu);
%% Computation of initial total energy
E_L1=-Omega(xl1,yl1,mu);
C_L1=-2*E_L1; % C_L1 = 3.6869532299 from Szebehely
E=E_L1+0.03715; % Offset as in figure 2.2 "LCS in the ER3BP"
%% Initial conditions range
x_0_min=-0.8;
x_0_max=-0.2;
vx_0_min=-2;
vx_0_max=2;
y_0=0;
% Grid initializing
[x_0,vx_0]=ndgrid(linspace(x_0_min,x_0_max,n),linspace(vx_0_min,vx_0_max,n));
vy_0=sqrt(2*E+2.*Omega(x_0,y_0,mu)-vx_0.^2);
% Kinetic energy computation
E_cin=E+Omega(x_0,y_0,mu);
% Inizializing
x_T=zeros(n,n);
y_T=zeros(n,n);
vx_T=zeros(n,n);
vy_T=zeros(n,n);
filtro=ones(n,n);
E_T=zeros(n,n);
delta_E=zeros(n,n);
a=zeros(n,n); % matrix of numbers of integration steps for each integration
np=0; % number of integrated points
fprintf('integro con n = %i\n',n)
%% Energy tolerance setting
energy_tol=0.1;
%% Setting the options for the integrator
RelTol=1e-12;AbsTol=1e-12; % From Short
% RelTol=1e-13;AbsTol=1e-22; % From JD James Mireles
% RelTol=3e-14;AbsTol=1e-16; % HIGH accuracy from Ross
options=odeset('AbsTol',AbsTol,'RelTol',RelTol);
%% Parallel integration of equations of motion
h=waitbar(0,'','Name','Integration in progress, please wait!');
S=zeros(n,n);
r1=zeros(n,n);
r2=zeros(n,n);
g=zeros(n,n);
for i=1:n
waitbar(i/n,h,sprintf('Computing i=%i',i));
parfor j=1:n
r1(i,j)=sqrt((x_0(i,j)+mu).^2+y_0.^2);
r2(i,j)=sqrt((x_0(i,j)-1+mu).^2+y_0.^2);
g(i,j)=((1-mu)./(r1(i,j).^3)+mu./(r2(i,j).^3));
if E_cin(i,j)>0 && isreal(vy_0(i,j)) % Check for real velocity and positive Kinetic energy
S(i,j)=g(i,j)*T;
[s,Y]=ode45(@f_reg,[0 S(i,j)],[x_0(i,j); y_0; vx_0(i,j); vy_0(i,j)],options,mu);
a(i,j)=length(Y);
% if s(a(i,j)) < 2
% filtro(i,j)=3;
% end
% Saving solutions
x_T(i,j)=Y(a(i,j),1);
vx_T(i,j)=Y(a(i,j),3);
y_T(i,j)=Y(a(i,j),2);
vy_T(i,j)=Y(a(i,j),4);
% Computation of final total energy and difference with
% initial one
E_T(i,j)=Energy(x_T(i,j),y_T(i,j),vx_T(i,j),vy_T(i,j),mu);
delta_E(i,j)=abs(E_T(i,j)-E);
if delta_E(i,j) > energy_tol; % Check of total energy conservation
fprintf(' Ouch! Wrong Integration: i,j=(%i,%i)\n E_T=%.2f \n delta_E=%f\n\n',i,j,E_T(i,j),delta_E(i,j));
filtro(i,j)=2; % Saving position of the point
end
np=np+1;
else
filtro(i,j)=0; % 1 = interesting point; 0 = non-sense point; 2 = bad integration point
end
end
end
close(h);
t_integrazione=toc;
%%
filtro_1=filtro;
for i=2:n-1
for j=2:n-1
if filtro(i,j)==2 || filtro (i,j)==3
filtro_1(i,j)=2;
filtro_1(i+1,j)=2;
filtro_1(i-1,j)=2;
filtro_1(i,j+1)=2;
filtro_1(i,j-1)=2;
end
end
end
fprintf('integato con n = %i\n',n)
fprintf('integato con energy_tol = %f\n',energy_tol)
fprintf('numero punti totali \t%i\n',n^2)
fprintf('numero punti integrati \t%i\n',np)
fprintf('tempo per integrare \t%.2f s\n',t_integrazione)
%% FTLE Computation
fprintf('adesso calcolo ftle\n')
tic
dphi=zeros(2,2);
ftle=zeros(n-2,n-2);
ftle_norm=zeros(n-2,n-2);
ds_x=(x_0_max-x_0_min)/(n-1);
ds_vx=(vx_0_max-vx_0_min)/(n-1);
for i=2:n-1
for j=2:n-1
if filtro_1(i,j) && ... % Check for interesting point
filtro_1(i,j-1) && ...
filtro_1(i,j+1) && ...
filtro_1(i-1,j) && ...
filtro_1(i+1,j)
% La direzione dello spostamento la decide il denominatore
% TODO spiegarsi teoricamente come mai la matrice pu<EFBFBD>
% essere ridotta a 2x2
dphi(1,1)=(x_T(i+1,j)-x_T(i-1,j))/(2*ds_x); %(x_0(i-1,j)-x_0(i+1,j));
dphi(1,2)=(x_T(i,j+1)-x_T(i,j-1))/(2*ds_vx); %(vx_0(i,j-1)-vx_0(i,j+1));
dphi(2,1)=(vx_T(i+1,j)-vx_T(i-1,j))/(2*ds_x); %(x_0(i-1,j)-x_0(i+1,j));
dphi(2,2)=(vx_T(i,j+1)-vx_T(i,j-1))/(2*ds_vx); %(vx_0(i,j-1)-vx_0(i,j+1));
if filtro_1(i,j)==2 % Manual setting to visualize bad integrated points
ftle(i-1,j-1)=0;
else
ftle(i-1,j-1)=(1/abs(T))*log(max(sqrt(abs(eig(dphi*dphi')))));
ftle_norm(i-1,j-1)=(1/abs(T))*log(norm(dphi));
end
end
end
end
%% Plotting results
% figure
% plot(t,Y)
% figure
% plot(Y(:,1),Y(:,2))
% figure
xx=linspace(x_0_min,x_0_max,n);
vvx=linspace(vx_0_min,vx_0_max,n);
[x,vx]=ndgrid(xx(2:n-1),vvx(2:n-1));
figure
pcolor(x,vx,ftle)
shading flat
t_ftle=toc;
fprintf('tempo per integrare \t%.2f s\n',t_integrazione)
fprintf('tempo per calcolare ftle \t%.2f s\n',t_ftle)
% ora=fstringf %TODO
% save(['var_' num2str(n) '_' num2str(clock(4)])
nome=['var_xvx_', 'ode00', '_n',num2str(n)];
save(nome)

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function [ x_T, y_T, vx_T, e_T, filter ] = Integrate_FILE( x_0, y_0, vx_0, e_0, T, N, mu, options)
%Integrate
% This function performs Runge-Kutta-Fehlberg integration for given
% initial conditions to compute FILE
nx=length(x_0);
ny=length(y_0);
nvx=length(vx_0);
ne=length(e_0);
vy_0=zeros(nx,ny,nvx,ne);
x_T=zeros(nx,ny,nvx,ne);
y_T=zeros(nx,ny,nvx,ne);
vx_T=zeros(nx,ny,nvx,ne);
vy_T=zeros(nx,ny,nvx,ne);
e_T=zeros(nx,ny,nvx,ne);
%% Look for phisically meaningful points
filter=zeros(nx,ny,nvx,ne); %0=meaningless point 1=meaningful point
%% Integrate only meaningful points
h=waitbar(0,'','Name','Integration in progress, please wait!');
for i=1:nx
waitbar(i/nx,h,sprintf('Computing i=%i',i));
for j=1:ny
parfor k=1:nvx
for l=1:ne
vy_0(i,j,k,l)=sqrt(2*Potential(x_0(i),y_0(j),mu)+2*e_0(l)-vx_0(k)^2);
if isreal(vy_0(i,j,k,l))
filter(i,j,k,l)=1;
ci=[x_0(i), y_0(j), vx_0(k), vy_0(i,j,k,l)];
[t,Y,te,ye,ie]=ode45(@f,[0 T], ci, options, mu);
x_T(i,j,k,l)=ye(N+1,1);
y_T(i,j,k,l)=ye(N+1,2);
vx_T(i,j,k,l)=ye(N+1,3);
vy_T(i,j,k,l)=ye(N+1,4);
e_T(i,j,k,l)=0.5*(vx_T(i,j,k,l)^2+vy_T(i,j,k,l)^2)-Potential(x_T(i,j,k,l),y_T(i,j,k,l),mu);
end
end
end
end
end
close(h);

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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)
%Integrate
% This function performs Runge-Kutta-Fehlberg integration for given
% initial conditions to compute FTLE to obtain the image in the Gawlick's
% article "Lagrangian Coherent Structures in the Elliptic Restricted
% Three-Body Problem".
nx=length(x_0);
ny=length(y_0);
nvx=length(vx_0);
ne=length(e_0);
vy_0=zeros(nx,ny,nvx,ne);
x_T=zeros(nx,ny,nvx,ne);
y_T=zeros(nx,ny,nvx,ne);
vx_T=zeros(nx,ny,nvx,ne);
vy_T=zeros(nx,ny,nvx,ne);
e_T=zeros(nx,ny,nvx,ne);
delta_e=zeros(nx,ny,nvx,ne);
%% Look for phisically meaningful points
filter=zeros(nx,ny,nvx,ne); %0=meaningless point 1=meaningful point
useful=ones(nx,ny,nvx,ne);
%% Integrate only useful points
useful(:,1,:,1)=0;
useful(:,1,:,3)=0;
useful(:,3,:,1)=0;
useful(:,3,:,3)=0;
%% Integrate only meaningful points
h=waitbar(0,'','Name','Integration in progress, please wait!');
for i=1:nx
waitbar(i/nx,h,sprintf('Computing i=%i',i));
for j=1:ny
parfor k=1:nvx
for l=1:ne
if useful(i,j,k,l)
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);
if isreal(vy_0(i,j,k,l))
filter(i,j,k,l)=1;
ci=[x_0(i), y_0(j), vx_0(k), vy_0(i,j,k,l)];
[t,Y]=ode45(@f_ell,[0 T], ci, options, mu, ecc);
if abs(t(end)) < abs(T) % Consider also negative time
filter(i,j,k,l)=3
end
x_T(i,j,k,l)=Y(end,1);
y_T(i,j,k,l)=Y(end,2);
vx_T(i,j,k,l)=Y(end,3);
vy_T(i,j,k,l)=Y(end,4);
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);
% Compute the goodness of the integration
delta_e(i,j,k,l)=abs(e_T(i,j,k,l)-e_0(l));
end
end
end
end
end
end
close(h);

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samples/Matlab/Lagr.m Normal file
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function [xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5] = Lagr(mu)
% [xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5] = Lagr(mu)
% Lagr This function computes the coordinates of the Lagrangian points,
% given the mass parameter
yl1=0;
yl2=0;
yl3=0;
yl4=sqrt(3)/2;
yl5=-sqrt(3)/2;
c1=roots([1 mu-3 3-2*mu -mu 2*mu -mu]);
c2=roots([1 3-mu 3-2*mu -mu -2*mu -mu]);
c3=roots([1 2+mu 1+2*mu mu-1 2*mu-2 mu-1]);
xl1=0;
xl2=0;
for i=1:5
if isreal(c1(i))
xl1=1-mu-c1(i);
end
if isreal(c2(i))
xl2=1-mu+c2(i);
end
if isreal(c3(i))
xl3=-mu-c3(i);
end
end
xl4=0.5-mu;
xl5=xl4;
end

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% Plot dei Lagrangian points
n=5;
mu=linspace(0,0.5,n);
for i=1:n
[xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5] = Lagr(mu(i));
figure (1)
hold all
plot(xl1, yl1, 's')
plot(xl2, yl2, 's')
plot(xl3, yl3, 's')
plot(xl4, yl4, 's')
plot(xl5, yl5, 's')
plot(-mu,0,'o')
plot(1-mu,0, 'o')
plot([-mu(i) xl4],[0 yl4])
end

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samples/Matlab/Poincare.m Normal file
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clear
%% Initial Conditions
mu=0.012277471;
T=10;
N=5;
C=3.17;
x_0=0.30910452642073;
y_0=0.07738174525518;
vx_0=-0.72560796964234;
vy_0=sqrt(-C-vx_0^2+2*Potential(x_0,y_0,mu));
k=0;
%% Integration
options=odeset('AbsTol',1e-22,'RelTol',1e-13,'Events',@cross_y);
[t,y,te,ye,ie]=ode113(@f,[0 T],[x_0; y_0; vx_0; vy_0],options,mu);
figure
%plot(ye(:,1),ye(:,3),'rs')
plot(ye(:,1),0,'rs')

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samples/Matlab/RK4.m Normal file
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function x = RK4( fun, tspan, ci, mu )
%RK4 4th-order Runge Kutta integrator
% Detailed explanation goes here
h=1e-5;
t=tspan(1);
T=tspan(length(tspan));
dim=length(ci);
%x=zeros(l,dim);
x(:,1)=ci;
i=1;
while t<T
k1=fun(t,x(:,i),mu);
k2=fun(t+h/2,x(:,i)+k1*h/2,mu);
k3=fun(t+h/2,x(:,i)+k2*h/2,mu);
k4=fun(t+h,x(:,i)+h*k3,mu);
x(:,i+1)=x(:,i)+(h/6*(k1+2*k2+2*k3+k4));
t=t+h;
i=i+1;
end
x=x';
% function events(x)
% dist=
% return
end

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samples/Matlab/distance.m Normal file
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function [ value,isterminal,direction ] = distance( t,y,mu )
% DISTANCE compute the distance from the attactors
% [ value,terminal,direction ] = distance( t,y )
d=1e-2; % FIXME
% TODO mettere if se tolleranza D-d<tol -> value=0
D=sqrt((y(1)+mu).^2+y(2).^2); % distance from the largest primary
value=d-D;
isterminal=1;
direction=0;
end

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clear all
tic
% initialize integration time T, f(x,t), discretization size n ----------------
T = 8;
x_min=0;
x_max=2;
y_min=0;
y_max=1;
n=50; % how many points per one measure unit (both in x and in y)
ds=1/(n-1);
x_res=(x_max-x_min)*n;
y_res=(y_max-y_min)*n;
grid_x=linspace(x_min,x_max,x_res);
grid_y=linspace(y_min,y_max,y_res);
advected_x=zeros(x_res,y_res);
advected_y=zeros(x_res,y_res);
% integrate all initial points for t in [0,T] --------------------------------
parfor i = 1:x_res
for j = 1:y_res
[t,X] = ode45(@dg,[0,T],[grid_x(i),grid_y(j)]);
% store advected positions as they would appear in (x,y) coords ------
advected_x(i,j) = X(length(X(:,1)),1);
advected_y(i,j) = X(length(X(:,2)),2);
end
end
%% Compute FTLE
sigma=zeros(x_res,y_res);
% at each point in interior of grid, store FTLE ------------------------------
for i = 2:x_res-1
for j = 2:y_res-1
% compute Jacobian phi -----------------------------------------------
phi(1,1) = (advected_x(i+1,j)-advected_x(i-1,j))/(2*ds);
phi(1,2) = (advected_x(i,j-1)-advected_x(i,j+1))/(2*ds);
phi(2,1) = (advected_y(i+1,j)-advected_y(i-1,j))/(2*ds);
phi(2,2) = (advected_y(i,j-1)-advected_y(i,j+1))/(2*ds);
% find max eigenvalue of phi'*phi ------------------------------------
lambda_max = max(abs(eig(phi'*phi)));
% store FTLE ---------------------------------------------------------
sigma(i,j) = log(lambda_max)/abs(2*T);
end
end
toc
%% plot FTLE field ------------------------------------------------------------
figure
contourf(grid_x,grid_y,sigma');
colorbar('location','EastOutside');
axis equal
shading flat

41
samples/Matlab/example.m Normal file
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clear all
tic
% initialize integration time T, f(x,t), discretization size n ----------------
T = 20;
f_x_t = inline('[v(2);-sin(v(1))]','t','v');
grid_min = -3.4;
grid_max = 3.4;
grid_width = grid_max-grid_min;
n = 35;
grid_spacing = grid_min:(grid_width/(n-1)):grid_max;
advected_x=zeros(n,n);
advected_y=zeros(n,n);
% integrate all initial points for t in [0,T] --------------------------------
for i = 1:n
for j = 1:n
[t,x] = ode45(f_x_t,[0,T],[grid_spacing(i),grid_spacing(j)]);
% store advected positions as they would appear in (x,y) coords ------
advected_x(n-j+1,i) = x(length(x(:,1)),1);
advected_y(n-j+1,i) = x(length(x(:,2)),2);
end
end
sigma=zeros(n,n);
% at each point in interior of grid, store FTLE ------------------------------
for i = 2:n-1
for j = 2:n-1
% compute Jacobian phi -----------------------------------------------
phi(1,1) = (advected_x(i,j+1)-advected_x(i,j-1))/(2*grid_width/(n-1));
phi(1,2) = (advected_x(i-1,j)-advected_x(i+1,j))/(2*grid_width/(n-1));
phi(2,1) = (advected_y(i,j+1)-advected_y(i,j-1))/(2*grid_width/(n-1));
phi(2,2) = (advected_y(i-1,j)-advected_y(i+1,j))/(2*grid_width/(n-1));
% find max eigenvalue of phi'*phi ------------------------------------
lambda_max = max(abs(eig(phi'*phi)));
% store FTLE ---------------------------------------------------------
sigma(i,j) = log(lambda_max)/abs(T);
end
end
toc
%% plot FTLE field ------------------------------------------------------------
figure
contourf(grid_spacing,grid_spacing,sigma);
colorbar('location','EastOutside');

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tic
clear
%% Range definition
n=200;
mu=0.1;
[xl1,yl1,xl2,yl2,xl3,yl3,xl4,yl4,xl5,yl5]=Lagr(mu);
C_L1=2*Omega(xl1,yl1,mu);
E_0=-C_L1/2+0.03715;
Y_0=0;
nx=n;
x_0_min=-0.8;
x_0_max=-0.15;
x_0=linspace(x_0_min, x_0_max, nx);
dx=(x_0_max-x_0_min)/(nx-1);
nvx=n;
vx_0_min=-2;
vx_0_max=2;
vx_0=linspace(vx_0_min, vx_0_max, nvx);
dvx=(vx_0_max-vx_0_min)/(nvx-1);
ny=3;
dy=(dx+dvx)/2;
y_0=[Y_0-dy Y_0 Y_0+dy];
ne=3;
de=dy;
e_0=[E_0-de E_0 E_0+de];
%% Definition of arrays of initial conditions
%In this approach, only useful pints are stored and integrated
m=1;
% x=zeros(1,nx*ny*nvx*ne);
% y=zeros(1,nx*ny*nvx*ne);
% vx=zeros(1,nx*ny*nvx*ne);
% e=zeros(1,nx*ny*nvx*ne);
% vy=zeros(1,nx*ny*nvx*ne);
filter=zeros(nx,3,nvx,3);
for i=1:nx
for j=1:ny
for k=1:nvx
for l=1:ne
v_y=-sqrt(2*Omega(x_0(i),y_0(j),mu)+2*e_0(l)-vx_0(k)^2);
if ~((j~=2) && (l~=2)) && isreal(v_y)
x(m)=x_0(i);
y(m)=y_0(j);
vx(m)=vx_0(k);
e(m)=e_0(l);
vy(m)=v_y;
filter(i,j,k,l)=1;
m=m+1;
end
end
end
end
end
%% Selection of useful points
%% Data transfer to GPU
x_gpu=gpuArray(x);
y_gpu=gpuArray(y);
vx_gpu=gpuArray(vx);
vy_gpu=gpuArray(vy);
%% Integration on GPU
N=1;
t0=0;
[x_f,y_f,vx_f,vy_f]=arrayfun(@RKF45_FILE_gpu,t0,N,x_gpu,y_gpu,vx_gpu,vy_gpu,mu);
%% Data back to CPU and GPU memory cleaning
clear x_gpu y_gpu vx_gpu vy_gpu
x_T=gather(x_f);
clear x_f
y_T=gather(y_f);
clear y_f
vx_T=gather(vx_f);
clear vx_f
vy_T=gather(vy_f);
clear vy_f
%% Construction of matrix for FTLE computation
X_T=zeros(nx,ny,nvx,ne);
Y_T=zeros(nx,ny,nvx,ne);
VX_T=zeros(nx,ny,nvx,ne);
VY_T=zeros(nx,ny,nvx,ne);
E_T=zeros(nx,ny,nvx,ne);
m=1;
for i=1:nx
for j=1:ny
for k=1:nvx
for l=1:ne
if filter(i,j,k,l)==1
X_T(i,j,k,l)=x_T(m);
Y_T(i,j,k,l)=y_T(m);
VX_T(i,j,k,l)=vx_T(m);
VY_T(i,j,k,l)=vy_T(m);
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);
m=m+1;
end
end
end
end
end
%% Compute filter for FTLE
filter_ftle=filter;
for i=2:(nx-1)
for j=2:(ny-1)
for k=2:(nvx-1)
for l=2:(ne-1)
if filter(i,j,k,l)==0 || filter (i,j,k,l)==3
filter_ftle(i,j,k,l)=0;
filter_ftle(i+1,j,k,l)=0;
filter_ftle(i-1,j,k,l)=0;
filter_ftle(i,j+1,k,l)=0;
filter_ftle(i,j-1,k,l)=0;
filter_ftle(i,j,k+1,l)=0;
filter_ftle(i,j,k-1,l)=0;
filter_ftle(i,j,k,l+1)=0;
filter_ftle(i,j,k,l-1)=0;
end
end
end
end
end
%% FTLE computation
[ftle, dphi]=Compute_FILE_gpu( X_T, Y_T, VX_T, E_T, dx, dy, dvx, de, N, filter_ftle);
%% Plot results
figure
FTLE=squeeze(ftle(:,2,:,2));
FTLE(1,:)=[];
% FTLE(2,:)=[];
FTLE(:,1)=[];
% FTLE(:,2)=[];
x_0(1)=[];
vx_0(1)=[];
pcolor(x_0, vx_0, FTLE')
shading flat
toc

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clear
mu=0.1;
x_0=linspace(-0.8, -0.15, 2)
y_0=zeros(1,2)
vx_0=linspace(-2, 2, 2)
vy_0=zeros(1,2)
ci=[1-mu-0.05 0 0.005 0.5290]
t0=[0;0]
T=[2;2]
tspan=2
arg1={@f;@f}
%tspan={[0 2],[0 2]};
arg=[mu;mu]
[X]=arrayfun(RK4_par,t0,T,x_0',y_0',vx_0',vy_0',arg)
% [X]=arrayfun(@f,[0;1],[ci;ci],[mu;mu]);
%Y=RK4(@f,tspan,ci,mu);
% figure
% plot(Y(:,1),Y(:,2))
% Y(end,1)