FOR  FOR For Loop


Usage
 
 The for loop executes a set of statements with an 
 index variable looping through each element in a vector.
 The syntax of a for loop is one of the following:
 
   for (variable=expression)
      statements
   end
 
 Alternately, the parenthesis can be eliminated
 
   for variable=expression
      statements
   end
 
 or alternately, the index variable can be pre-initialized
 with the vector of values it is going to take:
 
   for variable
      statements
   end
 
 The third form is essentially equivalent to for variable=variable,
 where variable is both the index variable and the set of values
 over which the for loop executes.  See the examples section for
 an example of this form of the for loop.
 