Plot functions about calculus of variations

Hello everyone,

I am new to Matlab.

My codes are:

syms a X(t) c T 
assume(T>0)
F(t) = int(a*X(t)-(c/2)*(diff(X(t))^2),t,0,T)
D = functionalDerivative(F,X) 
assume(a,'positive')
assume(c,'positive')
S = dsolve(D, X(0)==X0, X(T)==0)

I want to plot the solution S at time t, but did not know how to do it.

Thank you for helping!

[Julieth Santamaria]

First, you have to define your constants. Then, you can use the following two lines.

S(t)=subs(S)

ezplot(S(t),0,T)

[Haku Bo]

It wroked, thank you for the help Julieth!

Addtional question: I have tried fplot but it could not plot this function. If ezplot works better than fplot, then why it is not recommended?

[Julieth Santamaria]

Strickly speaking, for matlab S(t) is not a function. So fplot won't work.

[Walter Roberson]

I had no problem using fplot once I had substituted in enough values to make it a function of a single variable, such as

SS(t) = subs(S, {X0, a, c,T}, {152, -9.81, 13, 11});
fplot(SS)