how to upload a random excel file and read it

I am working on an assignment in which i want to develope a stand alone app (GUI) of curve fitting.

in which i need to get data input from a random excel file,and read that file to make a graph.

under 'upload file'i wrote this fuction

function pushbutton2_Callback(hObject, eventdata, handles)
a= uigetfile({'*.xlsx'},'select the excel file');
b=xlsread('a);

under 'calculate' i wrote this fuction

function pushbutton1_Callback(hObject, eventdata, handles)
x=dataset(:,1);
y=dataset(:,2);
p=polyfit(x,y,5);
xp=0:0.1:0.5;
yp=polyval(p,xp);
plot(x,y,'--',xp,yp);
grid;

-- its not working,i want matlab to open a 'select window' so a user can upload a rondom excel file(which contain data),and when the user click the 'calculate button' it will fit the curve.

Answer 1

[Sylvain]

The trick is that your functions have local variables, you need to send them out using the handles.

you may use the import data toolbox , and generate an import function.

before generating a function, template the out put

generate the code importfile.m and modify it so that your function is

function out = importfile(filename)
...
end

then use this function in your upload file button call back:

function pushbutton2_Callback(hObject, eventdata, handles)
    a= uigetfile({'*.xlsx'},'select the excel file');
    b = importfile(filename);
    handles.dataset = b;    
    guidata(hObject, handles);
end

now use the handles to retrieve the data and plot the results

function pushbutton1_Callback(hObject, eventdata, handles)
    x=handles.dataset(:,1);
    y=handles.dataset(:,2);
    p=polyfit(x,y,5);
    xp=0:0.1:0.5;
    yp=polyval(p,xp);
    plot(x,y,'--',xp,yp);
    grid;
end

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F