Startup file for user-defined options
Create a startup.m file in a folder on the MATLAB search path. Add commands you want executed at startup. For example, your startup.m file might include physical constants, defaults for Handle Graphics® properties, engineering conversion factors, or anything else you want predefined in your workspace.
To specify the current folder in MATLAB when it starts, set the Initial working folder preference, described in General Preferences.
At startup, MATLAB automatically executes the file matlabrc.m and, if it exists on the MATLAB search path, startup.m. The file matlabrc.m, which is in the matlabroot/toolbox/local folder, is reserved for use by MathWorks® and by system administrators on multiuser systems.