st: 'if' with labels but finds no observations

["Paul O'Brien" <paul.obrien@afe2.org.uk>]

Dear All,

I am not sure what the problem is here, but 'if' is not working for   
some date labels.
year_f is OK up to 2000/1 but beyond that give no observations.


.egen year_f = ncyear(date_v), m(4)


. table year_f
----------------------
  year_f |     Freq.
----------+-----------
 1997/98 |    44,023
 1998/99 |    42,654
  1999/0 |    42,944
  2000/1 |    42,127
  2001/2 |    41,520
  2002/3 |    41,463
  2003/4 |    40,057
----------------------


. table ageint if year_f==2000/1

----------------------
  ageint |     Freq.
----------+-----------
      12 |         5
      13 |        36
      14 |       131
      15 |       346
etc


. table ageint if year_f==2001/2

no observations

r(2000);

But there are observations for year_f==2001/2

 . table ageint year_f

------------------------------------------------------------------------ 
-
          |                            year_f
   ageint | 1997/98  1998/99   1999/0   2000/1   2001/2   2002/3    
2003/4
---------- 
+--------------------------------------------------------------
       10 |       1        1                          2        1         
1
       11 |       2        2        2                 1        2         
1
       12 |       2        3        2        5        4        3         
7
       13 |      13       20       17       36       22       20        
12
       14 |      73       49       64      131      110      101        
99
       15 |     238      259      238      346      362      302       
325

If I try -list- I get the same thing:

. list if year_f==2000/1

 Observation 129622

   clin_s~e          RC   clin_w~k                  connum           2   
     date   15-Feb-01        dob   04-Apr-63

etc

 
Observation 129623

   clin_s~e          RC   clin_w~k       D- 
CON     connum           1       date   07-Feb-01        dob   06-Apr 
-77

etc

 

. list if year_f==2001/2

This last command gives nothing.

Help gratefully received.

Paul

Dr Paul O'Brien
Westside Contraceptive Services
Raymede Clinic, Exmoor St, London
W10 6DZ
020 8962 4450 - tel
020 8962 4451 - fax
07900 495 118 - mob

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