WHILE  WHILE While Loop


Usage
 
 The while loop executes a set of statements as long as
 a the test condition remains true.  The syntax of a 
 while loop is
 
   while test_expression
      statements
   end
 
 Note that a conditional expression is considered true if 
 the real part of the result of the expression contains
 any non-zero elements (this strange convention is adopted
 for compatibility with MATLAB).
 