Updating 'Base' workspace values using a GUI

Hi all,

I would like to update a set of values in my 'base' workspace via a GUI by getting a user to enter values into separate 'edit text' fields and once a button is clicked, all values are sent to the 'base' workspace and updated. I have tried inputdlg however this is very basic and I'd prefer if someone provided an example using uicontrol or GUIDE.

I don't mind doing this via GUIDE or programmatically, however I'm completely new to this so I'd love to see an example code that I can use which simply allows a user to enter a value, hit a button, and the value then updates in the 'base' workspace.

Please see the example of where I'd like to start via the image.

[Stephen23]

Original question:

https://www.mathworks.com/matlabcentral/answers/412362-updating-workspace-variables-using-guide

"... which simply allows a user to enter a value, hit a button, and the value then updates in the 'base' workspace."

Dynamically accessing variables in other workspaces is not recommended. It is much more reliable and more efficient to pass variables as input/output arguments.

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[Craig Saunders]

Thank you Stephen, however, regardless of this being recommended or not - would you kindly provide an example of how this could be done? The input dialog is basic and id prefer to design the GUI myself.

Cheers

[Stephen23]

@Craig Saunders: the second link in my comment above has many examples.

Answer 1

[Dennis]

Here is an example how you can achieve what you asked for, however if you decribe what you want to do we probably come up with a better/safer/quicker solution.

 tf=uicontrol('style','edit','position',[100,20,100,20]);
  button=uicontrol('style','pushbutton','callback',{@badidea,tf});

function badidea(~,~,tf)
A=tf.String;
evalin('base',strcat('A=',A))
end

[Craig Saunders]

Thanks Dennis, however this code does not successfully run in 2016a.

[Dennis]

try to save the function as seperate .m file. I am not sure when Matlab introduced dot notation, this should work with older versions:

function badidea(~,~,tf)
A=get(tf,'String');
evalin('base',strcat('A=',A))
end

[Craig Saunders]

This unfortunately still doesn't run, Dennis

Craig

[Dennis]

You get some kind of error message?

[Craig Saunders]

'Function definitions are not permitted in this context'.

[Dennis]

You are copy & pasting everything in command line? Either save and run it as script or save the function as badidea.m and run the other 2 lines.

Answer 2

[Image Analyst]

I agree with Stephen that it's not recommended. There are ways to share data. See the FAQ: https://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

[Craig Saunders]

Thanks for your response. My main task is to change values stored in the base workspace which are linked to a Simulink model. I want to run the Simulink model and update the values in order to show a difference within the simulation. Ideally I'd like the values to be adjusted using a slider which would demonstrate these differences.

Craig