I'm trying to run a CR3BP script. It keeps saying that dS(4,1) is a 1 by 1 and and the right side of the equation is 0 by 0. I can't figure out why:
function [dS] = CR3BP(~, s, mu, ~)
% Initialize state at input epoch t.
dS = zeros(6,1);
% Retrieve components from current state.
x = s(1,1);
y = s(2,1);
z = s(3,1);
vx = s(4,1);
vy = s(5,1);
vz = s(6,1);
% Compute the distance from the smaller primary.
r_1 = sqrt((x + mu - 1)^2 + y^2 + z^2);
% Compute the distance from the larger primary.
r_2 = sqrt((x + mu)^2 + y^2 + z^2);
% Assign velocities along x, y and z axes of the CR3BP rotating-frame.
dS(1,1) = vx;
dS(2,1) = vy;
dS(3,1) = vz;
% Assign accelerations along x, y and z axes of the CR3BP rotating-frame,
% using equations of motion from the CR3BP model.
dS(4,1) = x + 2*vy - (1 - mu)*(x + mu)/(r_2^3) - ...
mu*(x - 1 + mu)/(r_1^3);
dS(5,1) = y - 2*vx - ((1 - mu)*y)/(r_2^3) - (mu*y)/(r_1^3);
dS(6,1) = -((1 - mu)*z)/(r_2^3) - (mu*z)/(r_1^3);
end
-----------------------------------------------------------------------------------------
ERROR below:
Unable to perform assignment because the size of the
left side is 1-by-1 and the size of the right side is
0-by-0.
Error in CR3BP (line 35)
dS(4,1) = x + 2*vy - (1 - mu)*(x + mu)/(r_2^3) - ...
Error in odearguments (line 92)
f0 = ode(t0,y0,args{:}); % ODE15I sets args{1} to yp0.
Error in ode45 (line 107)
odearguments(odeIsFuncHandle,odeTreatAsMFile, solver_name, ode, tspan, y0, options, varargin);
Error in Single_Shooting_Lyapunov_Main (line 49)
[t_cor, s_cor] = ode45('CR3BP', cor_tspan, cor_xinit, options);
