how to solve this error

y= C1*exp(m1*t)+C2*exp(m2*t)+E1*sin(omega1*t)+E2*cos(omega1*t)+E3*sin(omega2*t)+E4*cos(omega2*t);

dy=m1*C1*exp(m1*t)+m2*C2*exp(m2*t)+E1*omega1*cos(omega1*t)-E2*omega1*sin(omega1*t)+E3*omega2*cos(omega2*t)-E4*omega2*sin(omega2*t);

Y1=1.0/alpha^2*(f1-omegaf*x0-beta*x0.^3-Ga*x0.^5)*(exp(-alpha*t)+alpha*t-1);

Y2= x1/alpha*(1-exp(-alpha*t)-(omegaf*x1+3*beta*x0.^2*x1)*(t^3/6- 2*alpha*t^4/24 +3*alpha^2*t^5/120));

Y3=5*Ga*x0.^4*x1*t.^3/6;

Y4=6*beta*x0*x1.^2 +20*Ga*x0.^3*x1.^2*(t.^4/24- 4*alpha*t.^5/120);

Y5=5*Ga*x0.^9-5*x0.^4*f1*(t^4/24 - alpha*Ga*t^5/120-alpha*t^5/120);

Y6=[f1*omega1.^2-f1*omegaf+omegaf^2*x0-3*beta*f1*x0.^2+ 4*omegaf^2*beta*x0.^3+3*beta*x0.^5+omegaf*Ga*x0.^5+5*omegaf*x0.^5+ 3*beta*Ga*x0.^7+5*beta*x0.^7+ 5*alpha*Ga*x0.^4*x1+5*alpha*x0.^4*x1]*t^4/24;

Y7=[2*alpha*f1*omegaf + alpha*f1*omega1.^2+ omegaf.^2*x1 -6*beta*x1.^3 -2*alpha*omegaf.^2*x0+5*alpha*omegaf*Ga*x0 + 6*alpha*beta*f1*x0.^2- 8*alpha*beta*omegaf*x0.^3+5*alpha*omegaf*x0.^5-2*Ga*x0.^5-11*alpha*beta*Ga*x0.^7 +5*alpha*beta*x0.^7+24*beta*omegaf*x0.^2*x1+70*Ga*omegaf*x0.^4*x1+27*beta^2*x0.^4*x1-10*alpha^2*Ga*x0.^4*x1-5*alpha.^2*x0.^4*x1 -18*f1*beta*x0*x1+108*beta*Ga*x0.^6*x1-60*Ga*x0.^2*x1.^3-60*Ga*f1*x0.^3*x1+ 85*Ga^2*x0.^8*x1]*t^5/120;

x = x0 + Y1 + Y2 - Y3 - Y4 + Y5 + Y6 + Y7;

% if(j>20)
fprintf('%20.12f %20.12f %20.12f \n',t,x,y);
% end

% incrementation of the variables and of time
x0=x;
y0=y;
z0=x;
t=t0+h;
t0=t;
end

[Torsten]

Which error ? We can't run your code since you didn't provide the necessary parameters.