Info Catalog octave: Function Handles Anonymous Functions Inline Functions octave: Anonymous Functions

octave: Function Handles

 
 11.11.1 Function Handles
 ------------------------
 
 A function handle is a pointer to another function and is defined with
 the syntax
 
      @FUNCTION-NAME
 
 For example,
 
      f = @sin;
 
 creates a function handle called ‘f’ that refers to the function ‘sin’.
 
    Function handles are used to call other functions indirectly, or to
 pass a function as an argument to another function like ‘quad’ or
 ‘fsolve’.  For example:
 
      f = @sin;
      quad (f, 0, pi)
          ⇒ 2
 
    You may use ‘feval’ to call a function using function handle, or
 simply write the name of the function handle followed by an argument
 list.  If there are no arguments, you must use an empty argument list
 ‘()’.  For example:
 
      f = @sin;
      feval (f, pi/4)
          ⇒ 0.70711
      f (pi/4)
          ⇒ 0.70711
 
  -- : is_function_handle (X)
      Return true if X is a function handle.
 
DONTPRINTYET       See also: isa XREFisa, typeinfo XREFtypeinfo, *noteDONTPRINTYET       See also: isa XREFisa, typeinfo XREFtypeinfo, 
      class XREFclass, functions XREFfunctions.
 
  -- : S = functions (FCN_HANDLE)
      Return a structure containing information about the function handle
      FCN_HANDLE.
 
      The structure S always contains these three fields:
 
      function
           The function name.  For an anonymous function (no name) this
           will be the actual function definition.
 
      type
           Type of the function.
 
           anonymous
                The function is anonymous.
 
           private
                The function is private.
 
           overloaded
                The function overloads an existing function.
 
           simple
                The function is a built-in or m-file function.
 
           subfunction
                The function is a subfunction within an m-file.
 
      file
           The m-file that will be called to perform the function.  This
           field is empty for anonymous and built-in functions.
 
      In addition, some function types may return more information in
      additional fields.
 
      *Warning:* ‘functions’ is provided for debugging purposes only.
      Its behavior may change in the future and programs should not
      depend on any particular output format.
 
DONTPRINTYET       See also: func2str XREFfunc2str, *notestr2func:
DONTPRINTYET       See also: func2str XREFfunc2str, str2func

      XREFstr2func.
 
  -- : func2str (FCN_HANDLE)
      Return a string containing the name of the function referenced by
      the function handle FCN_HANDLE.
 
DONTPRINTYET       See also: str2func XREFstr2func, *notefunctions:
DONTPRINTYET       See also: str2func XREFstr2func, functions

      XREFfunctions.
 
  -- : str2func (FCN_NAME)
  -- : str2func (FCN_NAME, "global")
      Return a function handle constructed from the string FCN_NAME.
 
      If the optional "global" argument is passed, locally visible
      functions are ignored in the lookup.
 
      See also: func2str XREFfunc2str, inline XREFinline,
      functions XREFfunctions.
 

Info Catalog octave: Function Handles Anonymous Functions Inline Functions octave: Anonymous Functions