From | "Paul O'Brien" <paul.obrien@afe2.org.uk> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: RE: 'if' with labels but finds no observations |
Date | Fri, 23 Apr 2004 21:22:56 +0100 |
There is no reason to expect -if- to accept
value labels in this way. Unless explicitly
instructed, -if- deals with values, not
value labels. Thus
if ncyear == 2000/1
is being interpreted as
if ncyear == 2000
as the expression 2000/1 evaluates
to 2000. On the other hand you evidently
have no years that are 2001/2, i.e. 1000.5.
The syntax is
if <exp>
where <exp> denotes an expression, which will
be evaluated before being used.
On the other hand, something like this
should work:
tab ncyear if ncyear == "2000/1":name
Nick
n.j.cox@durham.ac.uk
Paul O'Brien
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.
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