.-
help for ^finddup^                                          
.-

Find non-unique values or observations
--------------------------------------

   ^finddup^ varlist [^if^ exp]^,^ [^nom^iss ^nol^ist ^k^eep]


^finddup^ identifies values or observations which are not unique, and 
lists each such value or observation together with the rank order in 
which it occurs. Optionally, this information can be added to the data 
set using the ^keep^ option. ^finddup^ display all duplicates, but by 
the use of the ^nomiss^ option, observations with missing values can 
be excluded from the analysis.

 
Options
-------

^nomiss^ requests that values or observations with missing values not 
be analyzed.

^nolist^ requests that results not be displayed. This may be useful when
used with the keep option and a current display of duplicates is not 
required.

^keep^ requests that a new variable, dupval, be added to the data set.   


Note
----

Non-unique observations can be identified by -finddup _all. Non-unique
values are identified by using less than the full varlist.


Examples
--------
. l       
       
            id      encountr  othervar      
  1.         1          1        1
  2.         1          1        7 
  3.         1          2        5
  4.         2          1        3
  5.         2          2        3
  6.         3          1        3
  7.         3          1        4
  8.         3          2       27
  9.         3          2        .
 10.         .          .        .
 11.         .          .        1
 12.         .          .        .
 
. finddup id encountr
                     
            id      encountr     dupval       
  1.         1          1          1     
  2.         1          1          2     
  6.         3          1          1   
  7.         3          1          2  
  8.         3          2          1   
  9.         3          2          2 
 10.         .          .          1  
 11.         .          .          2  
 12.         .          .          3  
 
. finddup id encountr, nom k  
                        
            id      encountr     dupval   
  1.         1          1          1 
  2.         1          1          2   
  6.         3          1          1 
  7.         3          1          2 
  8.         3          2          1 
  9.         3          2          2   
 
   

Author
------

        Fred Wolfe, Arthritis Research Center
        fwolfe@@southwind.net, 26 July 1997



Also see
--------

    chkdup in STB reprints Vol 1, page 30.
