Programming and Data Types |

**Help**

This section covers the following topics:

- Using the Help Browser
- Help on Functions from the Help Browser
- Help on Functions from the Command Window
- Topical Help
- Paged Output
- Writing Your Own Help
- Help for Subfunctions and Private Functions
- Help for Methods and Overloaded Functions

**Using the Help Browser**

Open the Help Browser from the MATLAB Command Window using one of the following means:

- Click on the blue question mark symbol in the toolbar.
- Select
**Help -> MATLAB Help**from the menu. - Type the word
`doc`

at the command prompt.

Some of the features of the Help Browser are listed below.

**For more information:** See Finding Information with the Help Browser in the MATLAB "Development Environment" documentation

**Help on Functions from the Help Browser**

To find help on any function from the Help Browser, do either of the following:

- Select the
**Contents**tab of the Help Browser, open the**Contents**entry labeled`MATLAB`

, and find the two subentries shown below. Use one of these to look up the function you want help on.

- Type
`doc`

`<functionname>`

at the command line

**Help on Functions from the Command Window**

Several types of help on functions are available from the Command Window:

- To list all categories that you can request help on from the Command Window, just type
- To see a list of functions for one of these categories, along with a brief description of each function, type
`help`

`<category>`

. For example, - To get help on a particular function, type
`help`

`<functionname>`

. For example,

**Topical Help**

In addition to the help on individual functions, you can get help on any of the following topics by typing `help`

`<topicname>`

at the command line.

**Paged Output**

Before displaying a lengthy section of help text or code, put MATLAB into its paged output mode by typing `more`

`on`

. This breaks up any ensuing display into pages for easier viewing. Turn off paged output with `more`

`off`

.

Page through the displayed text using the space bar key. Or step through line by line using **Enter** or **Return**. Discontinue the display by pressing the **Q** key or **Ctrl+C**.

**Writing Your Own Help**

Start each program you write with a section of text providing help on how and when to use the function. If formatted properly, the MATLAB `help`

function displays this text when you enter

MATLAB considers the first group of consecutive lines immediately following the function definition line that begin with `%`

to be the help section for the function. The first line without `%`

as the left-most character ends the help.

**For more information:** See Help Text in the MATLAB "Development Environment" documentation

**Help for Subfunctions and Private Functions**

You can write help for subfunctions using the same rules that apply to main functions. To display the help for the subfunction `mysubfun`

in file `myfun.m`

, type:

To display the help for a private function, precede the function name with `private/`

. To get help on private function `myprivfun`

, type:

**Help for Methods and Overloaded Functions**

You can write help text for object-oriented class methods implemented with M-files. Display help for the method by typing

where the file `methodname.m`

resides in subdirectory `@classname`

.

For example, if you write a `plot`

method for a class named `polynom`

, (where the `plot`

method is defined in the file `@polynom/plot.m`

), you can display this help by typing

You can get help on overloaded MATLAB functions in the same way. To display the help text for the `eq`

function as implemented in `matlab/iofun/@serial`

, type

Command and Function Syntax | Development Environment |