A very brief introduction to programming with m-files

You can use m-file scripts to automate computations. Almost anything typed at the command line can also be included in a m-file script. Lines in a m-file script are interpreted sequentially and the instructions are executed in turn. M-file scripts allow you to implement complex computations that cannot be readily achieved using commands at the command line. You can also create computational capabilities for other people to use.

There are some differences between MATLAB, MathScript, and Octave script files; these differences are typically not that significant. M-file scripts are text files and can be edited by any text editor. The script file must have an extension of ".m" and be in a directory that MATLAB knows about. M-file names should begin with a letter and only contain letters and numbers. Any other characters (space, dash, star, slash, etc.) will be interpreted as operations on variables and will cause errors. Also, M-file names should not be the same as variables in the workspace to differentiate between file names and variables.

M-file scripts interact with the current executing environment. Variables set before the script is executed can affect what happens in the script. Variables set in the script remain after the script has finished execution.

Comments document your code and help other users (and yourself several months down the road) understand how you have implemented your program. Comments begin with the character % ; any text in a line after the % is ignored by the script interpreter.

To correctly execute a script, the script file environment must know the directory in which the script resides.