Matlab Functions Types

• For function-call resolution order, see Matlab Function Precedence Order.

Aside from the main function, functions fall into the following categories:

• Main Function
• Nested Function
• Local Function
• Private Function
• Anonymous Function

Main Function

The main function is the first function defined in a function file; the term is meaningful only relative to local functions and nested functions. Conventionally the main function shares its name with the file.

Nested Function

See Matlab Nested Function.

Local Function

A local function is any function defined inside a script file (placed at the end of the file), or any non-nested function defined after the main function in a function file.

• All local functions in a file are peers: any of them can be called from the script’s commands or from the main function in a function file, and they may also call each other
• Their order has no effect
• Local functions cannot be called from another file or from the Command Window
  • You can, however, view the help comment of a local function with help myFun > myFun_local, where myFun_local lives inside the file myFun.m
• A local function may not share its name with the file

Private Function

• A private function has restricted accessibility: its .m file must live in a subfolder named private. Private functions can only be called from .m files in the immediate parent folder of that private folder
  • That immediate parent folder must be the Current Folder or a folder on the MATLAB path
  • Private functions cannot be called from the Command Window
  • The same code can also be invoked from the file itself, files in the same folder, or the Command Window in that folder — but in those contexts it is no longer “private”
• The code of a private function is no different from an ordinary function; you can also have a main function with sub-functions and nested functions inside the same .m file
• You can read the help comment of a private function with help private/private_fun

Anonymous Function

See Matlab Anonymous Function.