How to access to variables saved in Matlab folder from the GUI

I want to load my dataset or access any other variables that are saved to my matlab folder or are in my workspace currently from the matlab GUI I created. But when I call my functions on callback function of a button, I can't do it. Could you give me a simple example how to do it?

[per isakson]

"any other variables that are saved to my matlab folder" &nbsp do you mean saved in a mat-file in the current folder?

See evalin

[Ege]

Yes exactly. I mean mat files

Answer 1

[per isakson]

Add lines similar to the following, which are copied from the doc on load

    filename = 'durer.mat';
    myVars = {'X','caption'};
    S = load(filename,myVars{:})

to the callback function.

&nbsp

" or are in my workspace" &nbsp see evalin, Execute MATLAB expression in specified workspace and add

    my_variable = evalin( 'base', 'my_variable' )

to the callback function.

[Ege]

I want to select which database to work on on a popup menu so I tried following in my callback function according to your code:

contents = get(handles.popup_selectds,'String'); 
popupmenuvalue = contents{get(handles.popup_selectds,'Value')};
if popupmenuvalue== 'Dataset-1'
   filename = 'dataset.mat';
    S = load(filename)
elseif popupmenu4value== 'Dataset-2'
   filename = 'dataset2.mat';
    S = load(filename)
end

did not include

myVars = {'X','caption'};

section since I want all the data. But it did not load my datasets

[per isakson]

"But it did not load my datasets" &nbsp Try to be more specific. Is S empty or what?

I happen to have a file named dataset.mat in my cssm-folder. It contains an instance of the dataset class of the Statistic Toolbox

    >> S = load( 'dataset.mat' )
    S = 
        cereal: [77x7 dataset]

    >> whos -file dataset.mat
      Name        Size            Bytes  Class      Attributes

      cereal       -              19106  dataset

[Ege]

well S seems

S = 

      dataset: [5000x21 table]

But I cannot see anything in my workspace and I don't know how to access a column in my dataset or how to call my .m files which has code uses this dataset.

[Ege]

Sorry about it when I could not see anything in the workspace I assumed It could not load anything properly. Because after I try to access to S it gives error.

S = 

      dataset: [5000x21 table]

>> S
Undefined function or variable 'S'.

[per isakson]

• There should be a struct named S in the workspace of the callback function.
• Each variable of the mat-file should appear as a field of S

I guess you have a struct, S, with a field named dataset in the workspace of the callback function and want a copy of it in the base workspace.

Use assignin to make a copy in the base workspace

    assignin( 'base', 'my_dataset', S.dataset )

[Ege]

Thank you now I can see my loaded dataset in my workspace but still I can't do anything on it.

contents = get(handles.popup_selectds,'String'); 
popupmenu4value = contents{get(handles.popup_selectds,'Value')};
if popupmenu4value== 'Dataset-1'
   filename = 'dataset.mat';
    S = load(filename)
     assignin( 'base', 'dataset1', S.dataset )
     dosomething1
elseif popupmenu4value== 'Dataset-2'
   filename = 'dataset2.mat';
    S = load(filename)
     assignin( 'base', 'dataset2', S.dataset )
     dosomething2
end

In the do something I basically try to access some data but I can't:

churn=dataset2.churn;

Undefined variable "dataset2" or function "dataset2.churn".

Error in yap (line 16) churn=dataset2.churn;

Error in ChurnP>popup_selectds_Callback (line 111) dosomething2

Error in gui_mainfcn (line 95) feval(varargin{:});

Error in ChurnP (line 42) gui_mainfcn(gui_State, varargin{:});

Error in @(hObject,eventdata)ChurnP('popup_selectds_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating uicontrol Callback

[Ege]

Making the variables global and adding assigning solved my problem thank you very much for your help :)

[per isakson]

"I can't do anything on it"

• I assume that assignin actually assigned a variable in the base workspace
• load assigns a value to the variable S.&nbsp dataset2 is not a variable, but a field of the struct S. Try churn = S.dataset2.churn;.

Comments

• Do a few excercises with Access Data in a Structure Array
• Don't make it a habbit to use globals.