How to get an expression from a textbox in GUI?

Hi!

I'm working on a program in GUI which purpose is to solve non-linear equations. My idea is a simple interface with 4 buttons, axes and a text field where the user can write mathematical expressions (like @(x) 4-4*x^2-exp(x) ), hit a button with a predefined solver, and the program solves the eqation. (A have the functions for the solver already and it works) I know I should use the get() function to get the expression from the text field, but it cannot run, because there is an error somewhere. I tried to change the fromat of expression with str2sym() function but it didn't work. My idea is the following for the push button:

syms x 
f=str2sym(get(handles.edit1,'string'))
myfunction(f)

Thank you for your answers!

Answer 1

[Shadaab Siddiqie]

From my understanding you want to get a equation from the textbox of the GUI. You can use inline like so:

equ=get(handles.edit1,'Sring');
f=inline(equ,'x') % this makes function f with independent variable x, f(x)

In case there are multiple variables please refer inline.