 Usage:  z = var (x {,j})  
 
 Input:

  x                      d1 x d2 x ... x dn array 
                         
  j                      integer (number of dimension, default = 1) 
                         
 Output:

  z                      d1 x d2 x .. x d(j-1) x 1 x d(j+1) x .. x dn array 
                         
--------------------------------------------------------------
(C) MD*TECH Method and Data Technologies, 17.8.2000
