How to take function as input from textbox?

how can I take a function such as sin(x) or exp(x) as an input from the textbox in MATLAB gui?

t = get(handles.input,'string')
c = conv (t,t)
plot(c)

I have tried this but it does not work.

I want to convolve the signal but I can't figure out how to take input as a function

[Mehmed Saad]

do you mean user enters sin(x) or exp(x) in textbox or user enters the values like 1 2 3 4?

[Saad Rana]

I mean that the user enter sin(x) or cos(x) or exp(x) and functions like that

[Mehmed Saad]

and do you have x or user have to enter it? is it necessary to use text box (you can use dropdown)?

[Saad Rana]

yes I have a user to enter it and the textbox is necessary

Answer 1

[Mehmed Saad]

You can use any one of the following

1. eval
2. feval
3. str2func

For example

The string user enters in text box is

s = 'sin(x)';

eval will evaluate the string assuming that x is variable inside your function workspace in which you are evaluation eval

eval(s)

For feval and str2func user must enter the function name and not the argument

s = 'sin'
feval(s,x)

or

s = 'sin';
f = str2func(s);
f(x)