How to pass a variable from one file to another?

Hi all, I have a matlab function block in Simulink with a feedback. The input to the function is a constant that changes with the time. The function calls another function includes ode15s (File1) that must get their equations from another file (File2). I want to pass the value of B from the main matlab function file to File2 to be used there. I used global but that did not work. Any idea?

Matlab Function File:

function y  = fcn(B)
...
y=File1
%-----------------------------

File 1

function [t,x]=File1
....
[t,x] = ode15s(@File2,tspan,x0,opt);
%-----------------------------------

File2

function out= File2(t,x)
...
out=[some equations that use "B" as a constant]
%-----------------------------------------------------

%

[Easwar Kumar Yarrabikki]

When you say It Didn't work, How was the error looks like...?

[Ismaeel]

"The GLOBAL declaration must precede any use of the variable B."

[Ismaeel]

"Global declaration not resolved to a Data Store Memory block registered via the Ports and Data Manager."

Answer 1

[Walter Roberson]

Do not use global for that purpose.

https://www.mathworks.com/help/matlab/math/parameterizing-functions.html

[Ismaeel]

Thanks Walter, I read the document but still I have the same problem. I was wondering how there is no direct way to get the port value of the block and share it with other files?

[Walter Roberson]

"I was wondering how there is no direct way to get the port value of the block and share it with other files"

You can route the signal that is output from Subsystem2 to multiple blocks; each of them can receive B on input. Likewise you could route the output of the MATLAB Function Block to multiple blocks.

However, File1 and File2 are not blocks, they are MATLAB functions. You cannot route signals to or from them.

function y  = fcn(B)
...
y = File1(B)
%-----------------------------

function [t,x] = File1(B)
....
[t,x] = ode15s(@(t,x) File2(t,x,B), tspan, x0, opt);
%-----------------------------------

function out = File2(t, x, B)
...
out=[some equations that use "B" as a constant]
%----------------------------------------------------

Not a global in sight.

[Ismaeel]

I see now, thanks for the clarification.

[Ismaeel]

Sorry Walter, I have followed the nested method mentioned in the link you provided but unfortunately, it is not supported using matlab function block.

[Walter Roberson]

Hmmm, as indicated in one of your other Questions recently, that should be supported provided that the function handle is buried like is shown. What error message are you receiving?

[Ismaeel]

I am trying to upload a picture of the error but there is something prevents it after uploading it. Anyway, this is what i got: Nested functions are not supported.

Function 'MF' (#83.127.128), line 8, column 15: "f" Launch diagnostic report.

[Walter Roberson]

If you have multiple functions in the same file, make sure each is terminated with "end" as soon as it is finished.

function y  = fcn(B)
...
y = File1(B)
end
%-----------------------------

function [t,x] = File1(B)
....
[t,x] = ode15s(@(t,x) File2(t,x,B), tspan, x0, opt);
end
%-----------------------------------

function out = File2(t, x, B)
...
out=[some equations that use "B" as a constant]
end
%----------------------------------------------------

Answer 2

[Ismaeel]

Also, I added a block "To Workspace" with the name "B" but still B is undefined.