Trouble substituting a value into a symbolic expression for use with fplot

I'm having difficulty understanding what I'm doing wrong here:

syms x a
f=exp(x-a);
g=subs(f,'a',sym(0));
fplot(g,[-5 5])

I get the error:

Error using fcnchk (line 103)
If FUN is a MATLAB object, it must have an feval method.Error in fplot (line 61)
   fun = fcnchk(fun);

If I explicitly define g as being a symbolic function:

fplot(@(x)g,[-5 5])

Undefined function 'isfinite' for input arguments of type 'sym'.

Error in fplot (line 113)
  J = find(isfinite(y));

I clearly am not understanding the way the symbolic toolbox works and would appreciate a pointer.

Answer 1

[Alexander]

The command fplot only takes function handles, not symbolic objects. The easiest way to plot symbolic objects is using ezplot:

 ezplot(g,[-5 5])

If you want to use fplot, you can use the command matlabFunction to convert the symbolic object into a MATLAB anonymous function:

 fplot(matlabFunction(g),[-5 5])

[Bob]

Thanks, I also found casting g as a char worked for fplot :)

[work wolf]

@Bob and @ Alexander Thanks :)

[Walter Roberson]

fplot() does accept symbolic objects in modern versions, but did not when the question was originally asked.

[work wolf]

Dear, Walter Roberson. Thanks, I had problem about using symfun with fplot(). Thus, I used

matlabFunction(f)

instead of

symfun(formula,variables)

Please, see my Question here