Having trouble defining the following vector ode in matlab.
I have written the following for the right hand side function for suitable use in ode45. The system models a projectile with position and velocity vectors (x(t), y(t)) and (u(t), v(t)) at time t with parameters g and mu for gravity and air resistance.
function dydt = rhs_1(t, y, g, mu)
dxdt1 = u;
dydt2 = v;
dudt3 = -mu.*y(1).*sqrt(y(1).^2+y(2).^2);
dvdt4 = -g-mu.*y(2).*sqrt(y(1).^2+y(2).^2);
dydt = [dxdt1, dydt2, dudt3, dvdt4];
end
And when I run the following;
[t,y,g,mu]=ode45(@rhs_1,[0 100],[0.1; 0], 9.8, 0.5);
plot(t,y,g,mu(:,1),'r.-',t,y(:,2),'g.-','LineWidth',2,'MarkerSize',10);
I get the following error messages;
Unrecognized function or variable 'u'.
Error in rhs_1 (line 2)
dxdt1 = u;
Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});
Error in ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in runode (line 1)
[t,y,g,mu]=ode45(@rhs_1,[0 100],[0.1; 0], 9.8, 0.5);
Apologies if this is trivial, I am new to Matlab. Any help is greatly appreciated. Thank you!
