Undefined variable in workspace problem

Hello everyone,

there's a seemingly simple problem that I can't solve unfortunately. I'd like to run the following, very simple code:

function measVal = dataIn(step)

measVal = measurementValue(step,1);

end

where measurementValue is an n x 1 double array already loaded in my workspace. But when I try to run the code, I get the following error:

Undefined function or variable 'measurementValue'.

What could be the problem here? Thank you in advance for your help.

[KSSV]

What is measurementValue? Is it a function or variable? It seems it is a function, try to keep this function in the same pwd.

[Máté Torma]

No, it's an array filled with double values and loaded in the workspace:

Answer 1

[Stephen23]

"where measurementValue is an n x 1 double array already loaded in my workspace."

I guess you mean that it is loaded into the base workspace (every function has its own workspace):

https://www.mathworks.com/help/matlab/matlab_prog/base-and-function-workspaces.html

Because you did not pass that variable as an input argument to that function, it is NOT in that function workspace.

"But when I try to run the code, I get the following error: Undefined function or variable 'measurementValue'. What could be the problem here?"

Very simple: the variable is not in the function workspace.

Simplest and most efficient solution: pass it as an input argument.