The first line of your code is an assignment to a variable, rather than a 'function' or 'classdef'. In MATLAB terms, your code is a "script". In MATLAB, scripts cannot define functions.
In MATLAB, functions may only be defined in function files (files which start with "function" or in classdef files (files which start with "classdef").
You have two choices: You can make your first bit of code a function, or you can move the functions out in to their own .m files.
I also note that at the end after you have your function definitions, you have additional code that is not part of any function. I can tell it is not part of any function because you used the newer (better) syntax of having an "end" matching each "function", and so we can see that the code is after the end of the previous function. It is not possible to have such code in a function (or classdef) file.
