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Scripts versus Functions
Scripts are m-files containing MATLAB statements. MATLAB ``functions'' are another type of m-file. The biggest difference between scripts and functions is that functions have input and output parameters. Script files can only operate on the variables that are hard-coded into their m-file. As you can see, functions much more flexible. They are therefore more suitable for general purpose tasks that will be applied to different data.
Scripts are useful for tasks that don't change. They are also a way to document a specific sequence of actions, say a function call with special parameter values, that may be hard to remember.
There are more subtle differences between scripts and functions. A script can be thought of as a keyboard macro: when you type the name of the script, all of the commands contained in it are executed just as if you had typed these commands into the command window. Thus, all variables created in the script are added to the workspace for the current session. Furthermore, if any of the variables in the script file have the same name as the ones in your current workspace, the values of those variables in the workspace are changed by the actions in the script. This can be used to your advantage. It can also cause unwanted side effects.
In contrast, function variables are local to the function. (The exception is that it's possible to declare and use global variables, but that requires and explicit action by the user.) The local scope of function variables gives you greater security and flexibility. The only way (besides explicitly declared global variables) to get information into and out of a function is through through the variables in the parameter lists.
Example
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