MATLAB Programming

Variables
Initializing Persistent Variables. When you declare a persistent variable,
MATLAB initializes its value to an empty matrix, []. After the declaration
statement, you can assign your own value to it. This is often done using an
isempty statement, as shown here:
function findSum(inputvalue)
persistent SUM_X
if isempty(SUM_X)
SUM_X = 0;
end
SUM_X = SUM_X + inputvalue
This initializes the variable to 0 the first time you execute the function, and
then it accumulates the valueoneachiteration.
Naming Variables
MATLAB variable names must begin with a letter, which may be followed by
any combination of letters, digits, and underscores. MATLAB distinguishes
between uppercase and lowercase characters, so A and a arenotthesame
variable.
Although variable names can be of any length, MATLAB uses only the first
N characters of the name, (where N is the number returned by the function
namelengthmax), and ignores the rest. Hence, it is important to make
each variable name unique in the first N characters to enable MATLAB to
distinguish variables.
N = namelengthmax
N =
63
The genvarname function can be useful in creating variable names that are
both valid and unique. See the genvarname reference page to find out how to
do this.
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