Not Enough Input Arguments ode45

Question

0 개 추천

I have a coupled higher order set of ODE's to solve and plot. I have included my MATLAB files below.

F = m2(ddotdot - (L1+d)thetadot^2) + m2*g*sin(theta)
T = [(1/3)m1(L1)^2 + (1/12)m2(L2)^2 + m2(L1+d)^2]thetadotdot + (2(m2)(L1+d)ddot*thetadot + gcos(theta)[m1(L1/2) + m2(L1 + d

I used Euler's Method to bring F and T to first order equations.

I now want to used ode45 to solve this pair of equations.

I have 2 Matlab files:

ti = 0;
tf = 10;
theta0 = 0;
thetadot0 = 0;
d0 = 0;
ddot0 = 0;
[t,y]=ode45(@fdynamics,[ti tf],[theta0 thetadot0 d0 ddot0]);

AND

function fdynamics = myode(theta,thetadot,d,ddot)
F = 1;
T = 1;
m1 = 1;
m2 = 1;
g = 9.81;
l1 = 1;
l2 = 1;
fdynamics = zeros(2,1);
fdynamics(1) = (F-m2*g*sin(theta))/m2;
fdynamics(2) = (T-(2*m2*(l1+d))*thetadot*ddot -g*cos(theta)*(m1*(l1/2)+m2*(l1+d)) /((1/3)*m1*(l1)^2 + (1/12)*m2*l2^2 + m2(l1+d)^2));

When I click RUN, it says:

>> attempt
Not enough input arguments.
Error in fdynamics (line 14)
fdynamics(2) = (T-(2*m2*(l1+d))*thetadot*ddot
-g*cos(theta)*(m1*(l1/2)+m2*(l1+d)) /((1/3)*m1*(l1)^2 + (1/12)*m2*l2^2 +
m2(l1+d)^2));
Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.
Error in ode45 (line 115)
    odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options,
    varargin);
Error in attempt (line 7)
[t,y]=ode45(@fdynamics,[ti tf],[theta0 thetadot0 d0 ddot0]);