Matlab - Problema con explot en Matlab

s=tf('s')

Gr=0.762+0.0434/s;

G=2.5/(50*s^3+112.5*s^2+25.5*s+1);

tfin=20;

Go=series(Gr,G)

Gw=feedback(Go,1)

syms s

[numGr,denGr]=tfdata(Gr);

Gr_sym=poly2sym(numGr{1,1},'s')/poly2sym(denGr{1,1},'s')

[numG,denG]=tfdata(G);

G_sym=poly2sym(numG{1,1},'s')/poly2sym(denG{1,1},'s')

Go_sym=Gr_sym*G_sym

Gw_sym=Go_sym/(1+Go_sym)

gw_sym=ilaplace(Gw_sym);

figure

ezplot(Gw,[0 tfin]);

title('Pulse characteristics of the closed loop’)

axis auto

>> graficar_funcion_de_tranferencia

Transfer function:

s

Transfer function:

        1.905 s + 0.1085

---------------------------------

50 s^4 + 112.5 s^3 + 25.5 s^2 + s

Transfer function:

                1.905 s + 0.1085

------------------------------------------------

50 s^4 + 112.5 s^3 + 25.5 s^2 + 2.905 s + 0.1085

Gr_sym =

((381*s)/500 + 217/5000)/s

G_sym =

5/(2*(50*s^3 + (225*s^2)/2 + (51*s)/2 + 1))

Go_sym =

(5*((381*s)/500 + 217/5000))/(2*s*(50*s^3 + (225*s^2)/2 + (51*s)/2 + 1))

Gw_sym =

(5*((381*s)/500 + 217/5000))/(2*s*((5*((381*s)/500 + 217/5000))/(2*s*(50*s^3 + (225*s^2)/2 + (51*s)/2 + 1)) + 1)*(50*s^3 + (225*s^2)/2 + (51*s)/2 + 1))

>>