ISALPHA  ISALPHA Test for Alpha Characters in a String


Usage
 
 The isalpha functions returns a logical array that is 1 
 for characters in the argument string that are letters, and 
 is a logical 0 for characters in the argument that are not
 letters.  The syntax for its use is
 
    x = isalpha(s)
 
 where s is a string.  Note that this function is not
 locale sensitive, and returns a logical 1 for letters in the
 classic ASCII sense (a through z, and A through Z).
 