Defined a variable in work space:
The variables defined in the script will become a part of the workspace:
Your variables are:
i runsum vec
The Variables which are defined in the Command Window can be used in the script, but cannot be used in a function. For illustration, the vector vec could be defined in the Command Window (rather than in the script), but used in the script:
>> vec = 1:7;
This, though, is very bad programming style. It is much better to pass the vector vec to the function.
It is possible, in a MATLAB and also in other languages, to have global variables which can be shared by functions. Though there are similar cases in which using global variables is efficient, it is normally regarded as the poor programming style.