MATLAB: How to make a “local global ” variable

global variableMATLAB

Hello,

I would like to share some variables among some functions. It is inconvenience to make them all as arguments, because that makes the command too long. Is there a way to add these variable in a special "global variable pool"? A global variable is defined under all functions, which is not appropriate for me. I only want them to be shared among several functions.

Thank you for any helpful suggestion.

Best Answer

No, that does not exist.

you can create accessor functions that deal with persistent variables inside a private directory
you can put the functions togther in a class with class variables
if all relevant functions can be in the same source file, then you can use nested functions with shared variable
or pass a struct instead

Related Solutions

MATLAB: How to make a constant global so all packages files use it

As Stephen has explained already, passing variables as arguments is the best practice.

If you have really good reasons to define a constant globally, do not use global, but prefer a dedicated function, which provides the values as struct:

function C = myPackageConstants()
C.g  = 9.81;
C.pi = 3.14159265;
C.VolumeOfHeidelbergBarrel = 221716;  % liter

Then call this from all function as:

C = myPackageConstants;

This is less clear than using arguments. If it is called very often, it might matter that it has a certain runtime overhead. But in opposite to globals, you can be sure that the values are not modified anywhere, such that debugging gets horrible.

MATLAB: Use global variable in another GUI.

You have to declare a variable as global in each function you want to use it, of course. Otherwise it would be easy to let Matlab crash massively by declaring any frequently used variables like "x" or "K" globally as global.

It is explained in the documentation clearly, how globals are used. Therefore a

doc global

would help already.

Note that global variables are known to cause troubles and impede the debugging. Clean code does not contain any global variables for this reason. Better store the data in a figure and share its data using e.g. the ApplicationData.

Best Answer

Related Solutions

MATLAB: How to make a constant global so all packages files use it

MATLAB: Use global variable in another GUI.

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