Function failed to evaluate on array inputs; vectorizing the function may speed up its evaluation and avoid the need to loop over array elements

I need to create a selection of plots for 5 different values of v however with the below code I get a several copies of the same plot as well as the above error message. Does anyone know what is wrong? or a faster way?

a = char('a')

v = 0.0

V = 1+v;

g = @(a) (2048*(V.^4) + 128*(V.^2)*a.^6 + a.^12 + 16*V*sqrt(16384*(V.^6) + 2048*(V.^4)*a.^6 + 80*(V.^2)*a.^12 + a.^18)).^(1/3);

r =@(a) (1/16*V)*( a.^4 + a.^8./g(a) + g(a) );

alpha= @(a) (a/r(a));

A= @(a) 2*pi*(r(a).^2)*(1+sqrt(1-alpha(a).^2));

eps = @(a) 1/2*(A(a)/(4*pi-pi*a.^2)-1);

w = @(a) (1-cos (sin(alpha(a))))*eps(a) + (eps(a).^2);

hold all
%plot w with respect to a between 0.3-0.8 for v=0.00, 0.02, 0.03, 0.04,
%0.05 on seperate graphs

ezplot(w,[0.3,0.8])

clear v

v=0.02

figure

ezplot(w,[0.3,0.8])

etc.......