MATLAB: Accessing Table from Workspace from Matlab Editor.

workspace gui matlab editor

Hello,

I have a created a GUI which gets data from different sources, apply some modifications on these tables. For some other calculations, I need to access these tables in order to modify them again for other calculations.

The first thing I did, is to create a listbox which will scan my workspace

vars = evalin('base','who'); set(handles.listbox32,'String',vars)

Then each time I will click on one of the variables, i will be able to transform the dataset, for example here, as a FINTS.

i have 2 tables in my ws : A and B but can j or K.

so my code is the following :

for i = 1:numel(who)

if get(handles.listbox32, 'value') == i % normally A will correspond to 1 and B to 2.

%Access the Table. and make a fints(table) tvar = evalin('base','who') TableName = char(tvar(i,1)) Dates = TableName(:,1) Data = TableName(:,2) fints(Dates,Data)

This is not working mainly because TableName is being considered as a string and hence no kind of relation with table A.

Do you know how to make the link with the first table in my workspace and calibrate it each time I click on any handles.listbox which will point to some other table….

Thank you very much

Davin.

Best Answer

Davin - any code that you add to your question can be formatted so that is a easier to read. Just highlight the code portions and press the {} Code button. So your last comment would become more like

 tvar = evalin('base','who') ;
 TableName = char(tvar(i,1));
 Dates = TableName(:,1) ;
 Data = TableName(:,2);
 fints(Dates,Data);

Since your table is in the base workspace, and you get the table name via the list of variables returned by evalin, you could just re-use evalin to evaluate the command to return the first or second column of data from that table. Something like

 Dates = evalin('base',[TableName '(:,1);']);
 Data  = evalin('base',[TableName '(:,2);']);

The above should work, but there could be alternatives without having to access information in the workspace. Why not just copy the two (or more) tables to the GUI, saving them as fields within the handles structure (if you are designing your GUI using GUIDE)? Is there a reason that these tables must remain in the workspace, outside of the GUI?

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MATLAB: How to create a UITABLE in GUI using a data from matlab variable workspace

Nik - you could put this code in either the _CreateFcn for the uitable, or the _OpeningFcn of your GUI. If the former, then the code would be something like

 function uitable1_CreateFcn(hObject, eventdata, handles)
 % check to see if the variable exists in the base workspace
 if evalin('base','exist(''Table'',''var'')')
    % get the variable from the base workspace and save it to the table
    data = evalin('base','Table');
    set(hObject,'Data',data);
 end

The above code would be near-identical for the _OpeningFcn - all you would have to do is replace hObject with handles.uitable1.

Note how the above code checks to see if the variable exists before trying to access it using evalin.

In the above example, Table was created in the workspace as

 Table = randi(255,12,4);

MATLAB: Evalin Loop Workspace fints

Davin - have you tried stepping through the code to see what is happening? Let's suppose that you have a function called myFunc, and you have the five (fints) tables in the workspace. In the Command Window you type

 myFunc

Now suppose the definition for this function uses your second code example

 function myFunc
 Global = []
 a = who
 for i = 1:length(a)
    Data = evalin('base', [a{i}.Close])
    Global = [Global; Data(:,2)]
 end

The first line of code declares an empty array named Global. This should be renamed so as not to be confused with the built-in MATLAB global "qualifier" for global variables. Perhaps name it given the data that is being used to populate it: allCloseData. The next line calls the who function which, since we are evaluating it from a function, will return only those variables that have been declared in this function. I think that you want to grab the variables in the base workspace. So try

 allBaseVars = evalin('base','who');

Now, you iterate over each one and grab the last (close) column. You mentioned that you are concerned with accessing variables that aren't of type fints - so just add a check on the class type

 for k=1:length(allBaseVars)
    classType = evalin('base',['class(' allBaseVars{k} ')']);
    if strcmpi(classType,'fints')
       % do stuff
    end
 end

I don't have the Financial Toolbox so I'm guessing that the class type of a Financial Time Series object is fints. You can verify this easily enough by just type class(myFintsTable) in the Command Window and seeing what is returned.

Now we can "do stuff" if the object is of type fints. The code will be similar to what you have shown, but the expression (the second input to evalin) must be a string and not the statement hat you have shown

 data = evalin('base',[allBaseVars{k} '.Close']);
 allCloseData = [allCloseData ; data];

So your function now becomes

 function myFunc
 allCloseData = [];
 allBaseVars  = evalin('base','who');
 for k=1:length(allBaseVars)
    classType = evalin('base',['class(' allBaseVars{k} ')']);
    if strcmpi(classType,'fints')
       data = evalin('base',[allBaseVars{k} '.Close']);
       allCloseData = [allCloseData ; data];    
    end
 end

If you want to assign the allCloseData to the base workspace, then just add the following line of code to your function

 assignin('base', 'allCloseData', allCloseData);

Best Answer

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MATLAB: How to create a UITABLE in GUI using a data from matlab variable workspace

MATLAB: Evalin Loop Workspace fints

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