Known Software and Documentation Problems     Search    Help Desk 

Known Software Problems or Limitations

This section describes MATLAB 5.3 known software problems, providing workarounds for most problems.

Graphics

Printing with the HPGL Driver

The HPGL -dhpgl print driver does not perform clipping in MATLAB 5.3. As a result, the text labeling port names in Simulink blocks can extend beyond the rectangle, enclosing the block. Also, zooming in on line plots can produce lines that are not clipped to the axes box, (that is, it looks as if the line object's Clipping properties are set to off.

Microsoft Word users who import HPGL illustrations into documents will see no difference, because Word does not honor clipping.

dragrect and rbbox Functions

The dragrect function assumes that rectangles passed to it are specified in pixel units, not current figure units. To avoid incorrect scaling of rectangles when using dragrect, specify arguments in pixel units.

In function rbbox(initialRect,fixedPoint,stepSize), the stepSize argument is in pixel units. Arguments initialRect and fixedPoint are in the current figure units.

MinorGridLine Style Property Not Supported

The axes MinorGridLineStyle property, which is mentioned in Chapter 10 of the MATLAB 5.0 Using MATLAB Graphics manual and returned when you query axes properties, is not supported.

Application Program Interface

Avoid Modifying Input Arguments in MEX-Files

In MATLAB 5.1 to 5.3, MATLAB arrays can share data. There is currently no way for a MEX-file to determine that an array contains shared data. MEX-files that modify their input arguments may corrupt arrays in the MATLAB workspace. This style of programming is strongly discouraged.

Powerstation Fortran No Longer Supported

Powerstation Fortran 4.0 is no longer supported for MEX-files. DEC Visual Fortran 5.0 is supported.

Floating-Point Exceptions and Third-Party Libraries

MATLAB-based applications and MEX-files should never get floating-point exceptions. If you do get a floating-point exception, it may be that a third-party library that you link against has enabled floating-point exception handling. A floating-point exception may also occur if you use the wrong compiler options when building. For additional information, see the floating-point exception sections in the Application Program Interface Guide.

mexErrMsgTxt Warnings

If you get warnings when using mexErrMsgTxt, you may have a memory management compatibility problem. For more information, see "Memory Management Compatibility Issues" in the Application Program Interface Guide.

Microsoft Visual C++ Version 6.0 For Use with mex

You can use the Microsoft Visual C++ Version 6.0 compiler with mex. When installing Microsoft Visual C++ 6.0, if you need to change where this compiler is installed, you must change the location of the Common directory (at the appropriate installer dialog). If you change the location of the VC98 directory from its default setting, the mex script will not work properly.

MATLAB 4 MEX-Files

Beginning with MATLAB 5.2, MEX-files from MATLAB 4 do not run as is. You must recompile them in MATLAB 5.3 using the -V4 option of mex and a supported compiler.

Application Program Interface Guide

In the "Custom Building MEX-Files" section of the "System Setup" chapter, the MEX Script Switches table includes a -n switch. This switch does not exist.

PC-Specific Problems

The following problems apply to Microsoft Windows 95 and 98, as well as Windows NT platforms running MATLAB, unless otherwise indicated.

Help System

The setup program for Microsoft Visual C++ 6.0 or Visual J++ 6.0 installs a defective version of Microsoft's new HTML Help viewer. Some MATLAB components and toolboxes use the HTML Help viewer by default to display help. As a result, if either Visual C++ 6.0 or Visual J++ 6.0 is installed on your system, the MATLAB components and MathWorks products that use the viewer may display an error message when you invoke online help. The error message typically occurs when the help system attempts to display a single page of help (as opposed to a collection of help pages). The MATLAB components and MathWorks products affected by this problem are the Plot Editor, Page Layout dialog box, Report Generator, Simulink, and Stateflow.

Microsoft has an update to the HTML Help viewer that fixes this problem. The update is available as a self-installing program at

To install the update, download and run the self-installing program appropriate to your locale (for example, English). The whole process should take less than a minute.

If you experience any other problems with the HTML Help viewer or prefer to use a Web browser to view MATLAB documentation, you can disable use of the HTML Help viewer by resetting the matlab_use_html_help_viewer environment variable. Setting this variable to no causes MATLAB to display all help in the default Web browser on your system.

Set the environnment variable on a Windows 95 or 98 system by adding the following line

to your system's autoexec.bat file and rebooting your system. The autoexec.bat file is located in the root directory on your system's boot drive (typically, c:\).

On a Windows NT system, use the Environment pane of the Windows NT System Properties dialog box to set the environment variable. To display the System Properties dialog box, double-click the System folder in the Control Panel folder in the My Computer folder on your Windows NT desktop.

Avoid Spaces in Directory Names and Filenames

To ensure predictable results when running MATLAB on the PC, avoid using spaces in directory names and filenames for the locations you use for installing MATLAB and its ancillary products such as the compilers used for building MEX-files.

Following this recommendation shields you from a limitation in the Windows 95 and Windows NT command environment. If you do use spaces in such directory names or filenames, you may encounter problems stemming from the Windows command environment, such as messages about being unable to find files that are actually where you think they are.

Graphics Display Problems

If graphics objects in a MATLAB figure do not display correctly when the figure is updated during animations or when you drag objects, you may need to turn off hardware acceleration. Settings for controlling hardware acceleration are generally accessible from the Microsoft Windows 95 or NT Control Panel, in the Display settings. Consult your graphics hardware manual or contact your hardware vendor directly for information on making adjustments to your graphics hardware.

Tooltips Do Not Work on Windows 95 with comctl32.dll Version 4.00.950

The tooltip feature introduced in MATLAB 5.2 does not work with a certain configuration of Microsoft Windows 95 because of a bug in that operating system.

In particular, tooltips do not work on computers having version 4.00.950 of comctl32.dll. To determine which version of comctl32.dll you have, run the Microsoft Windows Explorer. In the Win95 directory, display the files in the System directory. Right-click on comctl32.dll and select Properties. Then, select the Version tab to see the version number.

Microsoft Internet Explorer 3 upgrades comctl32.dll to version 4.70; Internet Explorer 4 upgrades the file to version 4.71. Tooltips work with either version. Also, more recent versions of Windows 95 correct this problem. You can access the complete self-extracting archive file Com32upd.exe at

http://support.microsoft.com/download/support/mslfiles/Com32upd.exe

Note that even though your computer may have an upgraded version of comctl32.dll, if you are writing an application to be used by other users, they will not be able to take advantage of tooltips if their computers have the older version of the file.

Antivirus Software Can Conflict with mex and mbuild -setup Process

Certain PC antivirus software packages, such as Cheyenne AntiVirus and Dr. Solomon, can conflict with the mex -setup and mbuild -setup process. If during the setup of mex or mbuild, you receive an error message of this form

then you need to disable your antivirus software temporarily and rerun with the -setup option. After you have successfully rerun the setup operation, you can reenable your antivirus software.

Netscape Navigator

If you try to access (e.g., via the helpdesk command or the Simulink Help button) the HTML online documentation via the Netscape Navigator browser and the documentation does not appear, open the browser manually and then access the online documentation. In general, MATLAB automatically starts the browser for you, but in some Netscape Navigator installation configurations, the browser does not start automatically.

Note that not all earlier releases of Netscape Navigator Version 4 work well with the Help Desk; Netscape 4.0.4 does work well.

UNIX-Specific Problems

Graphical Installation Script May Not Work in Some Environments

The graphical installation script for Release 11 may not work properly under some UNIX X Window System environments. An example of a known environment in which the graphical installation script does not work is Redhat Linux 5.2 systems with the XFree86 3DLabs driver.

As a workaround, use the text-based installation script instead of the graphical installation script. To do so, type

and follow the text-based installation prompts on your screen. Those prompts are very similar to those used in the graphical installation script.


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