get a input function in GUI

if i input a function,eg.t^2, in the edit,how could i get the function in the M file? and when i type f=fourier(sin(t))*fourier(cos(t)) in the command window, it will show error "??? Undefined function or variable 't'.", how to solve this problem? Thank you~~~

Answer 1

[Paulo Silva]

a=get(handles.text1,'String'); %get the string from the textbox,example %a='t^2';
b=vectorize(a); %put dots before operations ^ / *
c=inline(b); %create one inline function from the string
t=0:0.1:10; %create a time vector, starts in t=0, step 0.1 seconds, ends t=10 s
c(t); %evaluate your function at each time vector point

For the fourier problem, t should be defined like a symbolic variable before the function being called

syms t

[José]

I've tried your answer, but I've get some errors.

??? Error using ==> sym.sym>tomupad at 2209

Conversion to 'sym' from 'inline' is not possible.

Error in ==> sym.sym>sym.sym at 111

S.s = tomupad(x,'');

Error in ==> subs at 64

r_unique_name = subs(sym(f_unique_name),varargin{:});

I'm also trying to input a function in an edit text from the GUI.

Thank you for your help.

[yo yoo]

I tried your answer to introduce functions, and it worked, thank you

Answer 2

[Olaitan Ibrahim]

Hello, pls I'm trying to use a get method in my gui program but I don't want all my inputs to remain in the edit box. Guys please help me out.

[Walter Roberson]

Please start a new Question for that topic, and be sure to include relevant code.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer