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Reference Guides
Reference guides are available for functions and commands supported by OML, Tcl, and Python.
Scripting Guide for OpenMatrix Language
OpenMatrix is a mathematical scripting language.
Functions
Functions are packets of statements that can be used repeatedly.
Variable Arguments
Functions can be written to accept or return an indefinite (or 'variable') number of arguments. To do so, use the varargin and varargout variables.

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Learn about the features and functionality available in Compose.
Reference Guides
Reference guides are available for functions and commands supported by OML, Tcl, and Python.
- Scripting Guide for OpenMatrix Language
  OpenMatrix is a mathematical scripting language.
  - Literals
    Literals are items that are constant throughout the life of the application. Literals include numeric, imaginary, characters, strings, logicals, and Other (NaN/Inf).
  - Data Types
    Data types are items that are constant throughout the life of the application and are built into the OpenMatrix language.
  - Strings
    Strings are arrays of characters.
  - Variables and Assignments
    OML language scripts manipulate data through variables. Variables are referred to by their name (alphanumeric) and can be created (assigned) and deleted as described in this section.
  - Indexing
    Indexing is used to retrieve one or more specific values out of a collection.
  - Operators
    Operators are used to combine operands.
  - Operator Descriptions (tables)
    Each operator in this section is explained with the operations of scalars, vectors, and matrices that are allowed for said operator.
  - Expressions and Statements
    Statements are made of expressions, which may be simple or complex.
  - Flow of Control and Looping
    Loops are used to perform the same set of statements multiple times.
  - Workspace and Scoping Rules
    There are two types of workspaces: Local and Global.
  - Functions
    Functions are packets of statements that can be used repeatedly.
    - Anonymous Functions
      Anonymous functions can be defined anywhere inside a script.
    - Clearing Functions
      Use the clear command (passing the function name as an argument) to clear (delete) a function from the session and make it inaccessible.
    - Eval
      Eval is a special function that accepts a string that is itself an OML script. The function evaluates the script and returns the appropriate value.
    - Function Calls
      Functions are packets of statements that can be used repeatedly. They can accept any number of inputs and can return any number of outputs.
    - Function Definitions
      Define functions using the function keyword.
    - Local Functions
      If a function is defined in its own file, the function name must match the file name.
    - nargin, nargout
      There are two special identifiers, nargin and nargout, that indicate the number of parameters passed into and the number of parameters returned from the function respectively.
    - Nested Functions
      Nested functions are functions within the main function.
    - Passing by Values
      Function arguments are passed by values in OpenMatrix language functions calls.
    - Recursion
      The function body can include calls to other functions and calls to itself. This is referred to as recursion.
    - Return
      Return is a special keyword that is only available in functions. It immediately ends the function.
    - Variable Arguments
      Functions can be written to accept or return an indefinite (or 'variable') number of arguments. To do so, use the varargin and varargout variables.
  - Scripts and Functions
    OpenMatrix statements persist in .oml files.
  - Files
    This section describes files that can be manipulated by the OpenMatrix Language.
  - Error and Warning Messages
    Errors and warning messages are both output in the console (or the Command Window in GUI mode) of Compose.
  - Plotting and Visualization
    Create 2D and 3D plots and control their style and appearance.
  - Objects in OpenMatrix Language
    Objects in OML are defined using the classdef keyword. This creates a blueprint for an object but does not actually create (instantiate) anything.
- Reference Guide for OpenMatrix Language Functions
  The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
- Python in Compose Reference Guide
Appendix
Get help for the optional libraries that are available in the Extension Manager.
Frequently Asked Questions
You've got questions? We've got answers!

Variable Arguments

Functions can be written to accept or return an indefinite (or 'variable') number of arguments. To do so, use the varargin and varargout variables.

In the most general form, a definition of a function with both variable input and output arguments would be:

varargout = function myfunc(varargin)

Note that varargout and varargin variables are cell arrays.