what to do so that matlab recognizes the guide script function?

when I do the script in the matlab guide if I use a command for example int (f, a, b) to find the area under the curve tells me that the function is not defined What should I do?

function pushbutton2_Callback(hObject, eventdata, handles)
syms 
a=str2double(get(handles.edit7,'string'));
b=str2double(get(handles.edit6,'string'));
x=linspace(a,b,500);
y=get(handles.edit4,'string')
j=char(y);
z=int(j,a,b);
set(handles.edit8,'string',z)
axes(handles.axes3);
area(x,y);
grid on;

Answer 1

[Walter Roberson]

Instead of

j=char(y);

you should

j = sym(y);

Then,

area(x,y);

should be

area(x, double(subs(y)));

[Erwin Avendaño]

Expression or statement is incorrect--possibly unbalanced (, {, or [.

set((handles.edit8,'string',z));

[Erwin Avendaño]

How to solve the error?

[Walter Roberson]

set(handles.edit8, 'string', char(z));

[Erwin Avendaño]

YOU ARE A GENIOUS! ¡¡¡¡¡¡¡¡THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!1