Evaluate Sym values

Hi, I trying to make a simple program, I would like to know how to make this

syms x; fun=x^2; x0=2;

x=x0; fun

And what a expect in the last line is 4 but I get X^2 How can I convert the sym to a double, I tried with doble(fun).

thank you

Answer 1

[Walter Roberson]

syms x;
fun=x^2;
x0=2;
subs(fun,x,x0)
double(ans)

Answer 2

[Behrooz Shahsavari]

If you want to evaluate that symbolic function in a large number of points (e.g. x = 1:10000), an effective way is to convert it to a MATLAB function handle as follows:

x0 = 1:10000;               % Assume that we want to evaluate the function in these points
FUN = matlabFunction(fun);  % This creates a function handle
y = feval(FUN, x0);         % Evaluates the new function handle at the specified points

[Zhe Chen]

matlabFunction is a very useful function.

Answer 3

[Paulo Silva]

try this way

fun=inline('x^2')
x0=2
fun(x0)

Answer 4

[Julio Cesar]

thank you!!! both work great :D