Section: FreeMat Functions
feval function executes a function using its name.
The syntax of feval is
[y1,y2,...,yn] = feval(f,x1,x2,...,xm)
where f is the name of the function to evaluate, and
xi are the arguments to the function, and yi are the
return values.
Alternately, f can be a function handle to a function
(see the section on function handles for more information).
Finally, FreeMat also supports f being a user defined class
in which case it will atttempt to invoke the subsref method
of the class.
feval to call the cos 
function indirectly.
--> feval('cos',pi/4)
ans = 
    0.7071 
Now, we call it through a function handle
--> c = @cos
c = 
 @cos
--> feval(c,pi/4)
ans = 
    0.7071 
Here we construct an inline object (which is a user-defined class)
and use feval to call it
--> afunc = inline('cos(t)+sin(t)','t')
afunc = 
  inline function object
  f(t) = cos(t)+sin(t)
--> feval(afunc,pi)
ans = 
   -1.0000 
--> afunc(pi)
ans = 
   -1.0000 
In both cases, (the feval call and the direct invokation), FreeMat
calls the subsref method of the class, which computes the requested 
function.