MATLAB: Error input must be floats, namely single or double.

MATLABnumerical method

tspan=[0:0.25:5];

syms x(t) m f_0

dx=diff(x)

x0=0;

ode=m*dx+k*x==f_0*sin(t)

[t,x]=ode45(@(t,x) ode,tspan,x0)

plot(t,x,'m')

Look at the documentation odeFunction for information on how to convert symbolic ode to numeric.

You are not calling ‘xdot’ correctly in your ode45 call.

Try this:

t = 0:.01:20;
x0 = [0 0]' + eps;
xdot = @(t,x) [0 1; 0 0] * x;
[T,X] = ode45(xdot,t,x0)
figure
plot(T, X)
grid

Also, the result is uniformly zero, so to prevent that, I added eps to ‘x0’.

Delete these two lines in your function and it works:

syms x1  x2  x3  x4  x5  v1  v2  v3  v4  v5;
x = [ x1 ,  x2 ,  x3 ,  x4 ,  x5 ,  v1 ,  v2 ,   v3 ,   v4 , v5]';