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Getting Help

• Prerequisites and Expectations for the Tutorial
• A Very Elementary MATLAB Tutorial
• Starting MATLAB
• Running the Demos
• Getting Help
• Creating Variables
• Performing Calculations
• Visualizing Data
• Creating Scripts with MATLAB Editor/Debugger
• Saving Variables and Sessions
• Working with Files, Directories and Paths

Introduction
MATLAB has an extensive help system built into it, containing detailed documentation and help information on all of the commands and functions of MATLAB. This help system is extremely useful for beginners to MATLAB, but even after becoming an expert at MATLAB, you will still use the help system to learn about other MATLAB functionalities that you have not yet used before. This lesson will show you how to use the MATLAB help system.

Getting Help From The Command Line
There are three main functions that you can use to obtain help on a given function: help, helpwin(short for help window) and doc (short for documentation). The functions help and helpwin give you the same information, but in a different window, the doc command returns an HTML page with a lot more information.

Below is the output of getting help on the date function, using the different functions.

help date

DATE Current date as date string. S = DATE returns a string containing the date in dd-mmm-yyyy format.

See also NOW, CLOCK, DATENUM.

Note: The output of help also refers to other functions that are related. In this example the help also tells you, See also NOW, CLOCK, DATENUM. You can now get help on these functions using the three different commands as well.

helpwin date

Click on image to see enlarged view.

Note: Though the content information from helpwin and help are the same there are advantages to using helpwin over help:
- The text is displayed in a separate window.
- You can just click on the functions listed under "See also" rather than having to type it in at the command prompt to view its help information.
- The Default Topics link will list all the function categories of MATLAB so that you can see the functions associated with a given category. For example, if you wanted to know what functions exist for plotting X verses Y you can click on the matlab\graph2d topic link.

doc date

Click on image to see enlarged view.

Note: The output of the doc command is the most complete. It not only breaks the information into sections, but also offers complete examples that can be studied and executed.

Try using the different help commands on the following functions: magic, fft, and surf.

Using the MATLAB Help Browser
Another source of help is the MATLAB help browser. You can invoke the MATLAB help browser by typing, helpbrowser, at the MATLAB command prompt, clicking on the help button , or by selecting Start->MATLAB->Help from the MATLAB desktop.

Click on image to see enlarged view.

The help browser has two main sections the Help Navigator, and the display pane. The display pane, as the name implies, displays the information selected. The Help Navigator is on the left hand side of the help browser, and should be used to navigate through the online help information. It includes the following things:

• Product filter - Set the filter to show documentation only for the products you specify.
• Contents tab - View the titles and tables of contents of documentation for your products.
• Index tab - Find specific index entries (selected keywords) in the MathWorks documentation for your products.
• Demos tab - View and run demonstrations for your MathWorks products.
• Search tab - Look for a specific word or phrase in the documentation. To get help for a specific function, set the Search type to Function Name.
• Favorites tab - View a list of links to documents you previously designated as favorites.

Of all these functionality the two most useful are the Contents tab and the Search tab. As noted above the Contents tab can be seen as the table of contents of the documentation. It is a great resource if you are looking to learn more about a given topic. The Search tab searches through all the documentation very efficiently, and also highlights the keywords that you are searching for in the document so that it is easier to read.

Try searching for help on the help browser itself.

Continue on to the next lesson.