Pass variable from GUI to function in MATLAB

Question

I have a MATLAB GUI that loads to aid in visually pre-processing data. Essentially it prompts the user to adjust the data range, reduce number of data points, etc... all while providing an updated graph. Upon completion of this work, I want to be able to close out the GUI and pass variables from the GUI to another MATLAB function that does the data analysis. I have found lots of information on how to pass information from a function TO and GUI, but not the other way around.

Any help would be greatly appreciated.

Answer 1

Matlab GUIs are functions: the code exists in a .m file just like other functions. Like regular functions, they can have return values. You can get as fancy as you want messing with the varargout system, or you can simply return a value, structure, or cell array containing whatever you want. Open up the m-file and edit it to return what you want it to.

Note: If you require special processing when the figure is being closed to generate the appropriate return value, you can reimplement the closeRequestFcn as you see fit.

Answer 2

Global variables can cause hard to find bugs. The best solution for your problem (where you want to pass the data directly to another function on close) might be to call the analysis function from the Figure Close Request Function. When the figure your GUI is running in is told to close, it will run the code in this function, which can call your analysis function and have access to the GUI's data.

Answer 3

The easy way: you declare as global variable, where variable stores the data that you want to carry from the GUI to the main MATLAB workspace. Then, you also declare the same global variable on the command window. Hereinafter, variable to be accesible from both scopes, the GUI and the main workspace.

You could also use save or any other alternatives as csvwrite or dlmwrite to store the data into a file, but this doesn't seem to be your case.