Convert lokal variables in to Global varibles.

i am using gui now in my Project. In order to see some results and use in further pushbuttons i used assignin .However when i want to use These structure Array which i created and made visisble by using assignin,i can not use it unfortunately. do you know any idea haw can i convert local variables in to global variables

Answer 1

[Jan]

By the way: Using assignin and global variables are bad programming practice. Try to avoid it and store the variables in the GUIs ApplicationData, e.g. by the guidata command. Search in this forum for "assignin" to get more opinions to this topic.

[Stephen23]

Although this sounds like an easy option, this can be complicated for beginners as GUIDE uses guidata for its own purposes and does not let you store data without first adding fields to the handles structure. The docs say:

GUIDE Uses guidata GUIDE uses guidata to store and maintain the handles structure. In a GUIDE code file, do not overwrite the handles structure or your program will no longer work. If you need to store other data, you can do so by adding new fields to the handles structure.

http://www.mathworks.com/help/matlab/ref/guidata.html

[cemsi888]

ok i can Transfer values but i want to see handles structure Array on Workspace too. Is ist possible that to see handles without writing assignin? i can see my handles on command window but unfortunateley not on Workspace!!

[Adam]

Why do you want to see variables in your base workspace when you are running a GUI front-end?

If you intend to use the results in other pushbutton callbacks you do not need the variables to go anywhere near the base workspace.

Using guidata is a two-way process - you push data into the GUI's stored data in one callback and in another you can pull it out again to use within the scope of that callback.

[Stephen23]

This need to use assignin is apparently common with German MATLAB users: I'm fascinated by the peculiar differences between question in goMatlab and MATLAB Answers: While the majority of German speaking beginners seem to transfer variables to functions by ASSIGNIN and EVALIN (and suffer from the resulting difficulties), this does rarely appear here

Quote from Jan Simon:

http://de.mathworks.com/matlabcentral/answers/1822-foreign-matlab-forums

@cemsi888: Learn to avoid assignin , those variables already have their own workspace, they don't need to be in the base workspace too! Use the debugging tools if you want to have a look at them while you are writing your code.

@Jan Simon: any idea on the origin of this cultural difference?

[cemsi888]

@ Adam i created structurearray which Name is Info. It contains Information about pfad file Name etc. My target is after i choose and read the article i want to see which file did i choose where can i this file find etc.. Yes you are right..In german matlabforums they generally advice to use assiginin and evalin...

Answer 2

[Stephen23]

Read the documentation for global. It has examples too, like this one:

function setGlobalx(val)
global x
x = val;

and

function r = getGlobalx
global x
r = x;

which you can use to store a value, and retrieve it later using, even from a different workspace.

[Image Analyst]

And read the FAQ too. http://matlab.wikia.com/wiki/FAQ#Are_global_variables_bad.3F If you're careful you can use globals without problem. Of course if you do dumb things in a function like assign a variable that you shouldn't have, then outside of that function the bad value will be seen regardless if you assigned it to a global variable or used setappdata()/getappdata() to assign/retrieve it.