How to plot a function, typed in a textfield (GUI), as a function handle?

Why does the following don't work or what needs to be added?

% --- Executes on button press in pbCalculate.
function pbCalculate_Callback(hObject, eventdata, handles)

x=handles.VarXStart:handles.VarXRes:handles.VarXEnd;
fh=@(x) handles.Function;
plot(x,fh(x))

"handles.Function" contains for example "x.^2" or "sin(x)" (it's a string). Typed into a textfield in the GUI by a user.

I've googled now a whole day long and couldn't find anything that worked... thanks for your help!

Answer 1

[Fangjun Jiang]

I am not sure if anonymous function can be defined that way. Try this:

str='x.^2';
f=inline(str);
x=0:0.1:4;
plot(x,f(x))

[Lukas]

Thank you very much! "inline()" works well.