Specifications

2 MATLAB GUIs

2-18

Defining Output Arguments – varargout

GUIDE defines callbacks to return a variable number of arguments using

varargout. See Passing Variable Numbers of Arguments for general

information on using

varargin and varargout.

Application Allows Only One Instance to Run

This option allows you to select between two behaviors for the GUI figure:

•Allow MATLAB to display only one instance of the GUI at a time.

•Allow MATLAB to display multiple instances of the GUI.

If you allow only one instance, MATLAB reuses the existing GUI figure

whenever the command to launch the GUI is issued. If a GUI already exists,

MATLAB brings it to the foreground rather than creating a new figure.

If you uncheck this option, MATLAB creates a new GUI figure whenever you

issue the command to launch the GUI.

Code in the Application M-File

GUIDE implements this feature by generating code in the application M-file

that uses the

openfig command. The reuse or new string specifies one instance

or multiple instances of the GUI figure.

fig = openfig(mfilename,'reuse');

fig = openfig(mfilename,'new');

Note Ensure that you have only one occurrence of openfig in your

application M-file, including in commented lines.

Using the System Background Colors

The color used for GUI components varies on different computer systems. This

option enables you to make the figure background color the same as the default

uicontrol background color, which is system dependent.