Error using plot Conversion to double from sym is not possible.

syms t 
f=2508+5.185*sin(0.00737*t)+3.813*sin(0.00737*t-4.318)+3.854*sin(0.00737*t-22.622)+5.103*sin(0.00737*t-154.853)+5.482*sin(0.00737*t-74.341);

j1=0.03; 
j2=0.03;
j3=0.03;
j4=0.03;
jrec=0.035;
kl=4.00e4;
k2=4.00e4;
k3=4.00e4;

J = [j1 0 0 0 ;0 j2+jrec 0 0 ;0 0 j3+jrec 0 ;0 0 0 j4+jrec ];

K = [kl -kl 0 0 ;-kl kl+k2 -k2 0 ;0 -k2 k2+k3 -k3;0 0 -k3 k3];

      T = J*diff(f)+K*t;

for t=0:720;
    plot(t,T)
end;
T;

Answer 1

[KSSV]

Your T is a class of sym, it got variable t in it. First substitute value of t, then convert it to double and then plot.

Like if t = 0 ;

t = 0 ;
T0 = subs(T,t) ;
T0 = double(T0) ;

Your T is matrix of 4X4 for each time step.