Chapter 10 MATLAB and the Internet In this chapter, we discuss a number of interrelated subjects: how to use the Internet to get additional help with MATLAB and to find MATLAB programs for certain specific applications, how to disseminate MATLAB programs over the Internet, and how to use MATLAB to prepare documents for posting on the World Wide Web. MATLAB Help on the Internet For answers to a variety of questions about MATLAB, it pays to visit the web site for The MathWorks, http://www.mathworks.com (In MATLAB 6, the Web menu on the Desktop menu bar can take you there automatically.) Since files on this site are moved around periodically, we won’t tell you precisely what is located where, but we will point out a few things to look for. First, you can find complete documentation sets for MATLAB and all the toolboxes. This is particularly useful if you didn’t install all the docu- mentation locally in order to save space. Second, there are lists of frequently asked questions about MATLAB, bug reports and bug fixes, etc. Third, there is an index of MATLAB-based books (including this one), with descriptions and ordering information. And finally, there are libraries of M-files, developed both by The MathWorks and by various MATLAB users, which you can download for free. These are especially useful if you need to do a standard sort of calcu- lation for which there are established algorithms but for which MATLAB has no built-in M-file; in all probability, someone has written an M-file for it and made it available. You can also find M-files and MATLAB help elsewhere on the Internet; a search on “MATLAB” will turn up dozens of MATLAB tutorials 214 Posting MATLAB Programs and Output 215 and help pages at all levels, many based at various universities. One of these is the web site associated with this book, http://www.math.umd.edu/schol/matlab where you can find nearly all of the MATLAB code used in this book. Posting MATLAB Programs and Output To post your own MATLAB programs or output on the Web, you have a number of options, eachwithdifferent advantages and disadvantages. M-Files, M-Books, Reports, and HTML Files First, since M-files (either script M-files or function M-files) are simply plain text files, you can post them, as is, on a web site, for interested parties to down- load. This is the simplest option, and if you’ve written a MATLAB program that you’d like to share with the world, this is the way to do it. It’s more likely, however, that you want to incorporate MATLAB graphics into a web page. If this is the case, there are basically three options: 1. You can prepare your document as an M-book in Microsoft Word. After debugging and executing your M-book, you have two options. You can simply post the M-book on your web site, allowing viewers with a Word installation to read it, and allowing viewers withbotha Word and a MATLAB installation to execute it. Or you can click on File : Save As ., and when the dialog box appears, under “Save as type”, select “Web Page (∗.htm, ∗.html)”. This will store your entire document in HTML (HyperText Markup Language) format for posting on the web, and will automatically convert all of the graphics to the correct format. Once your web document is created, you can modify it withany HTML editor (including Word itself). 2. If you’ve installed the MATLAB Report Generator, it can take your MATLAB programs and convert them into an HTML report with embed- ded graphics. 3. Finally, you can create your web document withyour favorite HTML editor and add links to your MATLAB graphics. For this to work, you need to save your graphics in a convenient format. The simplest way to do this is to select File : Export . in your figure window. Under “Save as type” in the dialog box that appears, you can for instance select “JPEG images (∗.jpg)”, and the resulting JPEG file can be incorporated into the document with a 216 Chapter 10: MATLAB and the Internet tag suchas <img src=sphere.jpg>. If you are not happy with the size of the resulting image, you can modify it with any image editor. (Almost any PC these days comes with one; in UNIX you can use ImageMagick C  , xv C  , or many other programs.) If you are planning to modify the image before posting it, it may be preferable to have MATLAB store the figure in TIFF format instead; that way no resolution is lost before you begin the editing process. ✓ If you are an advanced MATLAB user and you want to use MATLAB as an engine to power an interactive web site, then you might want to purchase the MATLAB Web Server, which is designed exactly for this purpose. You can see samples of what it can do at http://www.mathworks.com/products/demos/webserver/ Configuring Your Web Browser In this section, we explain how to configure the most popular Web browsers to display M-files in the M-file editor or to launch M-books automatically. Microsoft Internet Explorer If MATLAB and Word are installed on your Windows computer then Internet Explorer  should automatically know how to open M-books. With M-files, it may give you a choice of downloading the file or “opening” it; if you choose the latter, it will appear in the M-file editor, a slightly stripped-down version of the Editor/Debugger. Netscape Navigator The situation with Netscape Navigator  is slightly more complicated. If you click on an M-file (withthe .m extension), it will probably appear as a plain text file. You can save the file and then open it if you wish with the M-file editor. On a PC (but not in UNIX) you can open the M-file editor without launch- ing MATLAB; look for it in the MATLAB group under Start : Programs, or else look for the executable file meditor.exe (in MATLAB 5.3 and ear- lier, Medit.exe). If you click on an M-book (withthe .doc extension), your browser will probably offer you a choice of opening it or saving it, unless you have preconfigured Netscape to open it without prompting. (This depends also on your security settings.) What program Netscape uses to open Configuring Your Web Browser 217 Figure 10-1: The Netscape Preferences Panel. a file is controlled by your Preferences. To make changes, select Edit : Prefer- ences in the Netscape menu bar, find the Navigator section, and look for the “Applications” subsection. You will see a panel that looks something like Figure 10-1. (Its exact appearance depends on what version of Netscape you are using and your operating system.) Look for the “Microsoft Word Document” file type (withfile extension .doc) and, if necessary, change the program used to open suchfiles. Typical choices would be Word or Wordpad  in Windows and StarOffice  or PC File Viewer  in UNIX. Choices other than Word will only allow you to view, not to execute, M-books. . 10 MATLAB and the Internet In this chapter, we discuss a number of interrelated subjects: how to use the Internet to get additional help with MATLAB and. posting on the World Wide Web. MATLAB Help on the Internet For answers to a variety of questions about MATLAB, it pays to visit the web site for The MathWorks,