Mtalab code for given equation gives answer different than simulink model

how can I solve this equation by ode45 matlab code? Here z and zdot vary with time (t = 0:0.02:3) and simulation is also made for 3 seconds. My code gives answer different than that of Simulink model prepared for the same equation.Unable to figure out the reason or my matlab code is wrong? Equation is :

dydt = (-lambda)*(abs(zdot))*(Y)*(abs(Y)^(n-1))-(beta)*(z)*(abs(Y)^n) + ((A)*(zdot));

where,z = 2*t^2 , zdot= diff(z)

Function File: (Working) function dYdT = boucwen(t,Y) lambda = 1; beta = 0; A = 1.5; n = 2; syms t z = 2*t^2; zdot = diff (z); dydt = (-lambda)*(abs(zdot))*(Y)*(abs(Y)^(n-1))-(beta)*(z)*(abs(Y)^n) + ((A)*(zdot)); for t = 0:0.02:3 Z = z; Z = subs(z,t) Zdot = zdot; Zdot = subs(zdot,t) dYdT=dydt; dYdT=subs(dydt,t); end

m-script file for solution

timeperiod = [0:0.02:3] ; initialvalue = [0]; [t,Y] = ode45(@boucwen,timeperiod,initialvalue); plot(t,Y)