How do I fix a variable to a certain number??

Hi Im trying to fix a variable to a certain number.

I have set a variable called 'cx' as randi([10,30]) in GUI, but later on somehow it doesn't recognize cx and just leaves it as undefined. So when I define it again as randi([10,30]), obviously it gives another number, different from the initial one.. how do I fix this variable as a constant throughout the whole loop??

[Heejin Kim]

Oh by the way, from what I have written above, it might seem like the definition of cx is the problem, but what Im trying to do is just fix it as a constant. cuz cx=randi([10,30]) worked perfectly fine in other part of the loop

[Rick Rosson]

Please post your code, or at least a sub-set that shows an example of the issue.

[dpb]

"...it might seem like the definition of cx is the problem, but what I'm trying to do is just fix it as a constant."

Matlab does NOT have the concept of a constant variable (const in C, PARAMETER in Fortran). A variable is a variable; you can only keep it a constant once it's defined by ensuring by code logic that it is only ever defined that one time.

Answer 1

[Greig]

I suspect that cx is defined in a callback function somewhere, but is not passed back to the GUI handles, so that to the other GUI function, cx is undefined. Have a look at Share Data Among Callbacks or try

doc guidata

Or post part of your code and we can be more specific about how to fix it.

Answer 2

[mohammed alwaely]

how to fix this P/Po as one variable equal to zero???