ode45 system second order

Question

i have write this program but it's not working

function xprime = exh(t,z)
xprime = [z(2);
          30*z(3) - 40*z(1); 
          z(4);
          30*z(1)+30*z(5)-60*z(3);
          z(6);
          30*z(3)-40*z(5)];

tspan=[0,200];
Z0=[0.05 0.04 0.03];
[t,z] = ode45('exh',tspan,Z0);
plot(t,z)

Error in odearguments (line 87) f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0. Error in ode45 (line 113) [neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, odeFcn, ... — Kind Fatamii, Mar 03 '15 at 06:15

score 1 · Answer 1 · answered Mar 13 '15 at 10:24

1

Your system has dimension 6, your initial value has dimension 3, this can not work, the dimensions have to be the same.

In other words, you need not only the initial positions but also the initial velocities for a system of order 2.

answered Mar 13 '15 at 10:24

Lutz Lehmann

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ode45 system second order

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