This error message has two possible causes:
1. There is a user-defined function (.m file) that conflicts with a built-in MATLAB function.
For example, a user-defined function in a file named "plot.m" would conflict with the built-in MATLAB function "plot".
To resolve this issue, rename the user-defined function so it does not conflict with the built-in MATLAB function.
To determine the location of the function, open MATLAB and run the following command:
>> which -all <function name>
2. You are trying to provide inputs to a function, but have not defined it using the MATLAB function declaration.
For example, if the file "test1.m" is created without defining test1 as a function, and it is then passed an input argument, e.g.
This will cause the error if test1 was not previously defined as a function.
Hope this resolves the issue.