MATLAB: Function executing a Script – Intrested in Scripts Output

function call script

Hello,

I'm trying to combine my work in a simple function, which calls some Scripts. My Problem is that the OutputVariables won't show up in the Workspace (probably because functions use a different workspace than Scripts/CommandWindow). I want to use the function to declare a (global) variable that should be used in all Scripts. In the End I am interested in the Variables set in the Scripts.

My Function looks like:

function testfunction(x)
  global d;
  d = x; 
  Script1
end

and the Scripts do all kind of simple things:

%Script1
global d;
A = zeros(2,2);
A(1,1) = 3*d;

Now my Problem is that the Matrix A would not show up (in the WorkSpace) after calling 'testfunction(1)'. But if i worked in the CommandWindow with:

global d;
d = 3;
Script1

It would work as inteded. Obviously i run more Scripts and more complex things inside the Scripts. Reworking all Scripts as functions is the least thing i would like to do. I debuged and it confirmed that everything works well up to the point where the function ends. Then all the Variables I am interested in get cleared out of the workspace.

Thanks in Advance

Best Answer

See Jan's comments above, but for your problem, use this:

evalin('base','Script1')

Related Solutions

MATLAB: Problem with variable values across scripts

That would happen if the change to the variables is being made inside a function call. The change would to be made inside pure script levels to get it to stick.

Note: "run" is a function call.

MATLAB: Internal variables not calculated

Ok, I'm writing my own answer. The folks who answered previously were helpful, but I'm putting it together for anyone else who might stumble across this. The answer is that Matlab assumes that your function code is in a separate file. Because of this, variables that you want to pass between a calculation script file and a function definition file need to be explicitly declared as global variables in both places. So Matlab treats the single file like this:

File 1 (calculation script):

% Declare global variables and define them
global k q Q %etc

k = 8.99e9;  
q = 1e-6; 
%...
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%

% In the full script, I'm doing things with this function and these constants not 
% important to this discussion/problem.  I need to use the global variables in these calculations.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

File 2 (function script):

function f=rodForce(N)
    % Declare global variables (same as above)
    global k q Q %etc
    % Then do the function as in the OP
end

Or you could combine the two files as I have done (in the comment to a different answer). But global variables need to be declared both places (before the variables are defined and inside the function).

This is different from other programming languages (such as R and Python) when variables that aren't defined within a function are automatically inherited from the global environment (unless you restrict the environment within the funciton definition). And if no variable exists with that name, the error message is explicit.

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